NCS Method in Carpal Tunnel Syndrome (CTS) - For DM Neurology Students

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// ═══════════════════════════════════════════════════════════════════════════════
// SLIDE 1 — TITLE
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// ═══════════════════════════════════════════════════════════════════════════════
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    { num: "02", title: "NCS Parameters", sub: "Latency, amplitude, velocity - normal values" },
    { num: "03", title: "Standard Protocol", sub: "Motor → Sensory → Comparison studies" },
    { num: "04", title: "Inching Technique", sub: "Segmental stimulation for precise localization" },
    { num: "05", title: "Severity Grading", sub: "Mild / Moderate / Severe / Extreme" },
    { num: "06", title: "CTS + Diabetes", sub: "DPN background, pitfalls & internal comparison" },
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// ═══════════════════════════════════════════════════════════════════════════════
// SLIDE 3 — WHY NCS IN CTS?
// ═══════════════════════════════════════════════════════════════════════════════
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  header(s, "Why NCS in Carpal Tunnel Syndrome?", 0.18, C.white, C.teal);
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    { icon: "✔", title: "CONFIRM Diagnosis", body: "Differentiates CTS from C6/C7 radiculopathy, proximal median neuropathy, and diffuse polyneuropathy" },
    { icon: "📍", title: "LOCALIZE Compression", body: "Identifies the exact segment of focal slowing within the carpal tunnel using distal latency and inching technique" },
    { icon: "📊", title: "GRADE Severity", body: "Mild (sensory only) → Moderate (motor + sensory) → Severe (absent SNAP) → Extreme (axonal loss, denervation on EMG)" },
    { icon: "💊", title: "GUIDE Treatment", body: "Mild: splints / steroid injection   |   Severe: surgical decompression (carpal tunnel release)" },
    { icon: "📈", title: "MONITOR Progress", body: "Repeat NCS post-surgery or injection; sensory improvement precedes NCS normalization" },
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// ═══════════════════════════════════════════════════════════════════════════════
// SLIDE 4 — NCS PARAMETERS (with motor diagram image)
// ═══════════════════════════════════════════════════════════════════════════════
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// ═══════════════════════════════════════════════════════════════════════════════
// SLIDE 5 — SENSORY NCS (with SNAP image)
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    { name: "SNAP Amplitude", def: "Baseline → peak height (µV)", norm: "> 20 µV", key: false },
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  s.addText("⚡ Key Point: Sensory NCS is MORE SENSITIVE than motor NCS in early CTS.\nA prolonged median sensory latency is the EARLIEST NCS abnormality.", {
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// ═══════════════════════════════════════════════════════════════════════════════
// SLIDE 6 — STANDARD PROTOCOL
// ═══════════════════════════════════════════════════════════════════════════════
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  header(s, "Standard NCS Protocol for CTS", 0.18, C.white, C.navy);
  sectionTag(s, "PROTOCOL");

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      stim: "Wrist (8 cm from APB)", rec: "Abductor Pollicis Brevis (APB)",
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      step: "STEP 2", title: "Median SENSORY NCS (Antidromic)",
      stim: "Wrist", rec: "Ring electrodes Digit II or III",
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      step: "STEP 3", title: "Ulnar MOTOR + SENSORY NCS (Comparator)",
      stim: "Wrist", rec: "ADM (motor) | Digit V (sensory)",
      measure: "Latency and amplitude of both",
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    {
      step: "STEP 4", title: "Internal Comparison Studies",
      stim: "See next slide", rec: "See next slide",
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// ═══════════════════════════════════════════════════════════════════════════════
// SLIDE 7 — INTERNAL COMPARISON STUDIES (TABLE)
// ═══════════════════════════════════════════════════════════════════════════════
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  s.addText("Since both median and ulnar nerves travel through the same forearm, comparing their latencies at equal distances eliminates the effect of background polyneuropathy (e.g. DM neuropathy)", {
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    ["Median–Ulnar\nSensory Ring Finger", "Stimulate wrist, record at\nDigit IV (ring finger) antidromically", "Antidromic sensory", "Median > Ulnar\nby > 0.4 ms", "Useful when\npalmar study normal"],
    ["Median–Ulnar\nLumbrical–Interossei", "Stimulate at wrist, record at\n2nd interosseous space", "Motor comparison", "Median > Ulnar\nby > 0.4–0.5 ms", "Best for\nmotor CTS"],
    ["Median–Radial\nSensory to Thumb", "Stimulate median & radial at wrist\nRecord at thumb", "Antidromic sensory", "Median > Radial\nby > 0.5 ms", "Useful in\nsevere DPN"],
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// ═══════════════════════════════════════════════════════════════════════════════
// SLIDE 8 — INCHING TECHNIQUE (with images)
// ═══════════════════════════════════════════════════════════════════════════════
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  s.addImage({ path: "/home/daytona/workspace/ncs-cts-ppt/img2.png", x: 0.3, y: 0.9, w: 3.1, h: 3.7 });
  s.addText("Fig 36.3A: 12 stimulation sites\nin 1-cm increments across wrist.\nReference (0) = distal wrist crease", {
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    fontSize: 8.5, italic: true, color: C.slate, align: "center", fontFace: "Calibri"
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  // Right image - waveforms
  card(s, 3.65, 0.85, 6.1, 3.8, C.white, C.teal);
  s.addImage({ path: "/home/daytona/workspace/ncs-cts-ppt/img3.png", x: 3.72, y: 0.9, w: 5.95, h: 3.7 });
  s.addText("Fig 36.4: LEFT = CTS — abrupt latency jump at -2 cm (site of compression)\nRIGHT = Normal — linear latency increase of 0.16-0.21 ms per cm\nBradley & Daroff's Neurology", {
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  s.addText("Principle: Normal = ~0.16–0.21 ms/cm linear increase   |   Pathological = abrupt jump > 0.5 ms over a single 1-cm segment   |   CTS: focal slowing at / just distal to the transverse carpal ligament", {
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    fontSize: 10, bold: true, color: C.charcoal, align: "center", valign: "middle",
    fontFace: "Calibri"
  });
}

// ═══════════════════════════════════════════════════════════════════════════════
// SLIDE 9 — SEVERITY GRADING
// ═══════════════════════════════════════════════════════════════════════════════
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  addBg(s, C.offW);
  header(s, "NCS Severity Grading in Carpal Tunnel Syndrome", 0.18, C.white, C.teal);
  sectionTag(s, "GRADING");

  const grades = [
    {
      grade: "MILD", color: C.green, bg: "E8F5E9",
      findings: [
        "Prolonged median sensory latency / slowed SCV only",
        "Motor distal latency: NORMAL",
        "CMAP amplitude: NORMAL",
        "No denervation on EMG"
      ],
      tx: "Splints + NSAID / Steroid injection"
    },
    {
      grade: "MODERATE", color: "E65100", bg: "FFF3E0",
      findings: [
        "Prolonged motor AND sensory distal latencies",
        "SNAP amplitude reduced (but still present)",
        "CMAP amplitude may be mildly reduced",
        "No active denervation on EMG"
      ],
      tx: "Steroid injection → Consider surgical release"
    },
    {
      grade: "SEVERE", color: C.red, bg: "FFEBEE",
      findings: [
        "SNAP absent (median)",
        "Significantly prolonged motor latency",
        "Reduced CMAP amplitude (axonal loss)",
        "EMG: may show chronic neurogenic changes in APB"
      ],
      tx: "Surgical carpal tunnel release (urgent)"
    },
    {
      grade: "EXTREME", color: "4A148C", bg: "F3E5F5",
      findings: [
        "Absent SNAP and absent / minimal CMAP",
        "Fibrillations + positive sharp waves in APB (active denervation)",
        "Reduced / absent MUPs on voluntary activation",
        "EMG mandatory to assess axonal loss"
      ],
      tx: "Emergency surgical release; recovery guarded"
    },
  ];

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// ═══════════════════════════════════════════════════════════════════════════════
// SLIDE 10 — NORMAL VALUES TABLE
// ═══════════════════════════════════════════════════════════════════════════════
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    ["Peroneal", "Ankle", "EDB", "< 5.8", "> 2.0", "> 42", "< 58"],
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    ["Sural", "Calf", "Ankle", "< 4.4", "–", "> 6", "> 40"],
    ["Radial", "Forearm", "Thumb", "< 2.9", "–", "> 15", "> 50"],
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}

// ═══════════════════════════════════════════════════════════════════════════════
// SLIDE 11 — CTS IN DIABETES
// ═══════════════════════════════════════════════════════════════════════════════
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  sectionTag(s, "DM + CTS");

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      title: "Problem 1: Elevated Baselines",
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    {
      title: "Problem 2: DM is a CTS Risk Factor",
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      col: C.gold
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    {
      title: "Problem 3: Small Fiber DPN",
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    fontSize: 11, bold: true, color: C.white, align: "center", valign: "middle",
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// ═══════════════════════════════════════════════════════════════════════════════
// SLIDE 12 — NCS PROTOCOL IN DM + CTS
// ═══════════════════════════════════════════════════════════════════════════════
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  const s = pres.addSlide();
  addBg(s, C.offW);
  header(s, "NCS Protocol: CTS Superimposed on Diabetic Neuropathy", 0.18, C.white, C.teal);
  sectionTag(s, "DM PROTOCOL");

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    { n: 2, text: "Median motor NCS (wrist → APB) + ulnar motor NCS (comparator)" },
    { n: 3, text: "Median sensory NCS antidromic (wrist → Digit II)" },
    { n: 4, text: "Median–Ulnar palmar mixed comparison (most sensitive for CTS)" },
    { n: 5, text: "Median–Radial sensory to thumb (useful when DPN is severe)" },
    { n: 6, text: "Sural + peroneal NCS — grade severity of background DPN (lower limb worse in DPN)" },
    { n: 7, text: "If severe CTS suspected: Needle EMG of APB — fibrillations confirm axonal loss" },
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    ["Upper vs Lower", "Upper limb\nisolated", "Lower limb\nworse"],
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// ═══════════════════════════════════════════════════════════════════════════════
// SLIDE 13 — KEY EXAM POINTS
// ═══════════════════════════════════════════════════════════════════════════════
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    { num: "3", text: "Inching technique: normal = 0.16–0.21 ms/cm; pathological = abrupt jump >0.5 ms/cm at carpal ligament level", col: C.teal },
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    { num: "5", text: "Temperature MUST be >32°C before NCS — DM patients have cold extremities that falsely prolong latencies", col: C.tealLt },
    { num: "6", text: "Add needle EMG of APB in moderate–severe CTS: fibrillations & reduced MUP recruitment = axonal loss → surgical urgency", col: C.teal },
    { num: "7", text: "Post-surgical NCS improvement: sensory SYMPTOMS improve first; NCS latency normalization lags by months", col: C.gold },
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// ═══════════════════════════════════════════════════════════════════════════════
// SLIDE 14 — THANK YOU / REFERENCES
// ═══════════════════════════════════════════════════════════════════════════════
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    "1.  Bradley WG, Daroff RB et al. Bradley and Daroff's Neurology in Clinical Practice, 8th Ed. — Ch. 36 (EMG/NCS) & Ch. 106 (Median Nerve)",
    "2.  Adams RD, Victor M, Ropper AH. Adams and Victor's Principles of Neurology, 12th Ed. — Ch. 2 (Electrophysiologic Studies)",
    "3.  Campbell's Operative Orthopaedics, 15th Ed. — Carpal Tunnel Syndrome (NCS in diagnosis)",
    "4.  Kimura J. The carpal tunnel syndrome: localization of conduction abnormalities. Brain 1979;102:619–635.",
    "5.  American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) Practice Guidelines — CTS Electrodiagnosis",
  ];

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// ─── WRITE ───────────────────────────────────────────────────────────────────
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    shadow:{type:"outer",color:"000000",blur:4,offset:2,angle:135,opacity:0.08} });
}
function lbar(slide, x, y, h, color) {
  slide.addShape(pres.ShapeType.rect, { x, y, w:0.07, h,
    fill:{color}, line:{color} });
}
function circle(slide, x, y, d, fill, text, textColor) {
  slide.addShape(pres.ShapeType.ellipse, { x, y, w:d, h:d,
    fill:{color:fill}, line:{color:fill} });
  slide.addText(text, { x, y, w:d, h:d, margin:0,
    fontSize:13, bold:true, color:textColor||WHITE,
    align:"center", valign:"middle", fontFace:"Calibri" });
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 1  TITLE
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  s.background = {color:NAVY};

  // left accent
  s.addShape(pres.ShapeType.rect, {x:0,y:0,w:0.45,h:5.625,fill:{color:TEAL},line:{color:TEAL}});
  s.addShape(pres.ShapeType.rect, {x:0.45,y:0,w:0.07,h:5.625,fill:{color:GOLD},line:{color:GOLD}});

  s.addText("NCS in Carpal Tunnel Syndrome", {
    x:0.75, y:1.0, w:9.0, h:1.1,
    fontSize:38, bold:true, color:WHITE, fontFace:"Calibri", align:"left"
  });
  s.addText("Method, Interpretation & Special Considerations in Diabetes", {
    x:0.75, y:2.15, w:9.0, h:0.6,
    fontSize:19, color:TEAL2, fontFace:"Calibri", align:"left"
  });
  s.addShape(pres.ShapeType.rect,{x:0.75,y:2.88,w:4.8,h:0.055,fill:{color:GOLD},line:{color:GOLD}});
  s.addText("DM Neurology — Electrophysiology Seminar", {
    x:0.75, y:3.02, w:9.0, h:0.42,
    fontSize:14, italic:true, color:SLATE, fontFace:"Calibri", align:"left"
  });

  const chips = ["Motor NCS","Sensory NCS","Inching Technique","CTS + DM"];
  chips.forEach((c,i)=>{
    s.addShape(pres.ShapeType.rect,{x:0.75+i*2.25,y:4.7,w:2.1,h:0.42,
      fill:{color:TEAL,transparency:55},line:{color:TEAL2}});
    s.addText(c,{x:0.75+i*2.25,y:4.7,w:2.1,h:0.42,margin:0,
      fontSize:12,color:WHITE,align:"center",valign:"middle",fontFace:"Calibri"});
  });
  s.addText("Sources: Bradley & Daroff's Neurology in Clinical Practice  |  Adams & Victor's Principles of Neurology, 12th Ed.", {
    x:0.75,y:5.22,w:9.0,h:0.28,
    fontSize:8.5,italic:true,color:"4A6FA5",fontFace:"Calibri",align:"left"
  });
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 2  WHY NCS IN CTS
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  s.background = {color:OFFWH};
  topBar(s, NAVY, "Why NCS in Carpal Tunnel Syndrome?");
  tag(s, "RATIONALE");

  const items = [
    {icon:"✔", head:"CONFIRM Diagnosis",     body:"Differentiates CTS from C6/C7 radiculopathy, proximal median neuropathy, and diffuse polyneuropathy", col:TEAL},
    {icon:"📍",head:"LOCALIZE Compression",  body:"Identifies the exact segment of focal slowing within the carpal tunnel — distal latency + inching technique", col:TEAL2},
    {icon:"📊",head:"GRADE Severity",         body:"Mild (sensory only) → Moderate (motor+sensory) → Severe (absent SNAP) → Extreme (axonal loss + EMG denervation)", col:NAVY},
    {icon:"💊",head:"GUIDE Treatment",        body:"Mild: splints / steroid injection   |   Severe: surgical carpal tunnel release", col:GOLD},
    {icon:"📈",head:"MONITOR Recovery",       body:"Repeat NCS post-surgery / injection; sensory symptom improvement precedes NCS latency normalisation", col:TEAL},
  ];
  items.forEach((it,i)=>{
    const y = 0.88 + i*0.89;
    lbar(s, 0.28, y, 0.74, it.col);
    box(s, 0.38, y, 9.28, 0.74, WHITE, LGRAY);
    s.addText(it.icon+"  "+it.head, {x:0.52,y:y+0.05,w:2.8,h:0.35,
      fontSize:12.5,bold:true,color:it.col===GOLD?CHAR:it.col,fontFace:"Calibri"});
    s.addShape(pres.ShapeType.rect,{x:3.4,y:y+0.16,w:0.04,h:0.42,fill:{color:LGRAY},line:{color:LGRAY}});
    s.addText(it.body, {x:3.52,y:y+0.1,w:5.9,h:0.52,
      fontSize:11,color:CHAR,fontFace:"Calibri",valign:"middle"});
  });
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 3  NCS PARAMETERS — MOTOR
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  s.background = {color:OFFWH};
  topBar(s, TEAL, "NCS Parameters — Motor (CMAP)");
  tag(s, "MOTOR NCS");

  // diagram placeholder box
  box(s, 0.28, 0.84, 4.1, 2.9, "E8F4F7", TEAL);
  s.addText("MOTOR NCS SETUP", {x:0.38,y:0.9,w:3.9,h:0.38,
    fontSize:13,bold:true,color:TEAL,align:"center",fontFace:"Calibri"});
  s.addText([
    {text:"Stimulate: ",options:{bold:true}},{text:"Median nerve at WRIST (site 1)\n"},
    {text:"Stimulate: ",options:{bold:true}},{text:"Median nerve at ELBOW (site 2)\n"},
    {text:"Record: ",options:{bold:true}},{text:"Abductor Pollicis Brevis (APB)\n\n"},
    {text:"Distal Latency (A') ",options:{bold:true,color:RED}},{text:"= stimulus → CMAP onset\n"},
    {text:"Proximal Latency (B') ",options:{bold:true,color:TEAL}},{text:"= elbow stimulus → CMAP onset\n\n"},
    {text:"MCV = Distance C ÷ (B' − A')",options:{bold:true,color:NAVY}},
  ],{x:0.42,y:1.34,w:3.82,h:2.2,
    fontSize:11,color:CHAR,fontFace:"Calibri",valign:"top"});

  // Parameter table
  const rows = [
    ["Parameter","Reflects","Normal (Median)"],
    ["Distal Latency","Conduction through carpal tunnel → APB","< 4.2 ms"],
    ["CMAP Amplitude","Number of functioning motor axons","> 4.4 mV"],
    ["Motor CV","Speed of fastest fibers (forearm segment)","> 49 m/s"],
    ["F-Wave Latency","Proximal conduction integrity","< 31 ms"],
  ];
  s.addTable(rows.map((row,ri)=>row.map((cell,ci)=>({
    text:cell,
    options:{
      fontSize:11, bold:ri===0,
      color:ri===0?WHITE:(ci===2?TEAL:CHAR),
      fill:ri===0?NAVY:(ri%2===0?WHITE:OFFWH),
      align:"center", valign:"middle",
      border:{pt:0.5,color:"C5D5E0"}, fontFace:"Calibri"
    }
  }))),{x:4.55,y:0.84,w:5.18,h:2.9,rowH:0.58,colW:[1.7,2.3,1.18]});

  // Key rule
  box(s, 0.28, 3.85, 9.44, 0.62, "FFF8E1", GOLD);
  s.addText("⭐  In CTS: ONLY the distal motor latency is prolonged — the forearm MCV is NORMAL (confirms focal slowing within the tunnel, not a diffuse neuropathy)", {
    x:0.45,y:3.88,w:9.1,h:0.55,
    fontSize:11.5,bold:true,color:CHAR,fontFace:"Calibri",valign:"middle"
  });

  // Formula box
  box(s,0.28,4.55,9.44,0.82,NAVY,NAVY);
  s.addText("Motor Conduction Velocity  =  Distance between stimulation sites (mm)  ÷  [Proximal Latency − Distal Latency (ms)]", {
    x:0.42,y:4.57,w:9.1,h:0.76,
    fontSize:13,bold:true,color:WHITE,align:"center",valign:"middle",fontFace:"Calibri"
  });
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 4  NCS PARAMETERS — SENSORY
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  s.background = {color:OFFWH};
  topBar(s, TEAL, "NCS Parameters — Sensory (SNAP)");
  tag(s, "SENSORY NCS");

  // SNAP diagram box
  box(s, 0.28, 0.84, 3.5, 4.5, "E8F4F7", TEAL);
  s.addText("SNAP WAVEFORM", {x:0.38,y:0.9,w:3.3,h:0.35,
    fontSize:13,bold:true,color:TEAL,align:"center",fontFace:"Calibri"});

  // ASCII-art style waveform labels
  const waveLabels = [
    {label:"Onset Latency",desc:"Stimulus → first deflection from baseline",col:RED},
    {label:"Peak Latency", desc:"Stimulus → peak of SNAP",col:TEAL},
    {label:"Amplitude",    desc:"Baseline to peak height (measured in µV)",col:NAVY},
    {label:"Duration",     desc:"Width of the negative phase",col:SLATE},
    {label:"Area",         desc:"Area under negative phase curve",col:SLATE},
  ];
  waveLabels.forEach((w,i)=>{
    const y = 1.3 + i*0.73;
    s.addShape(pres.ShapeType.rect,{x:0.38,y,w:0.2,h:0.48,fill:{color:w.col},line:{color:w.col}});
    s.addText(w.label,{x:0.65,y:y+0.02,w:3.0,h:0.24,
      fontSize:11,bold:true,color:w.col===GOLD?CHAR:w.col,fontFace:"Calibri"});
    s.addText(w.desc,{x:0.65,y:y+0.25,w:3.0,h:0.22,
      fontSize:9.5,color:SLATE,italic:true,fontFace:"Calibri"});
  });

  // Right: parameters
  s.addText("Normal Values — Antidromic Median SNAP\n(Wrist stimulation → Digit II, ~13–14 cm)", {
    x:4.05,y:0.87,w:5.7,h:0.55,
    fontSize:13,bold:true,color:NAVY,fontFace:"Calibri"
  });

  const snapRows = [
    ["Parameter","Normal Value","Significance"],
    ["Onset Latency","< 3.5 ms","MOST SENSITIVE — first to prolong"],
    ["Peak Latency","< 3.6 ms","Easier to measure (less shock artifact)"],
    ["SNAP Amplitude","> 20 µV","Reduced = axonal loss"],
    ["Sensory CV","> 50 m/s","Slowed = demyelination"],
    ["Ulnar sensory","< 3.1 ms | >17 µV","Comparator — should be NORMAL in CTS"],
  ];
  s.addTable(snapRows.map((row,ri)=>row.map((cell,ci)=>({
    text:cell,
    options:{
      fontSize:10.5, bold:ri===0||(ri===1&&ci===2),
      color:ri===0?WHITE:(ci===2?TEAL:CHAR),
      fill:ri===0?TEAL:(ri===1?"E3F2FD":(ri%2===0?WHITE:OFFWH)),
      align:"center",valign:"middle",
      border:{pt:0.5,color:"C5D5E0"}, fontFace:"Calibri"
    }
  }))),{x:4.05,y:1.5,w:5.7,h:2.7,rowH:0.54,colW:[1.55,1.35,2.8]});

  // Big key point
  box(s,4.05,4.28,5.7,1.05,NAVY,NAVY);
  s.addText("⚡ KEY POINT", {x:4.2,y:4.32,w:5.4,h:0.28,
    fontSize:12,bold:true,color:GOLD,fontFace:"Calibri"});
  s.addText("Sensory NCS is MORE SENSITIVE than motor NCS in early CTS. A prolonged median sensory latency is the EARLIEST NCS abnormality — before any motor changes appear.", {
    x:4.2,y:4.6,w:5.4,h:0.68,
    fontSize:11,color:WHITE,fontFace:"Calibri",valign:"top"
  });
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 5  STANDARD PROTOCOL
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  s.background = {color:OFFWH};
  topBar(s, NAVY, "Standard NCS Protocol for CTS");
  tag(s, "PROTOCOL");

  const steps = [
    {n:"1",title:"Median MOTOR NCS",
     stim:"Wrist (7–8 cm from APB)  →  Elbow",
     rec:"Abductor Pollicis Brevis (APB)",
     measure:"Distal latency, CMAP amplitude, motor CV",
     abnormal:"DML > 4.2 ms; forearm MCV normal (focal tunnel slowing)",col:TEAL},
    {n:"2",title:"Median SENSORY NCS  (Antidromic)",
     stim:"Wrist",rec:"Ring electrodes at Digit II or Digit III (13–14 cm)",
     measure:"Onset latency, peak latency, SNAP amplitude, SCV",
     abnormal:"Onset latency > 3.5 ms; reduced SNAP amplitude; slowed SCV",col:TEAL2},
    {n:"3",title:"Ulnar MOTOR + SENSORY NCS  (Comparator)",
     stim:"Wrist",rec:"ADM for motor  |  Digit V for sensory",
     measure:"Latency and amplitude for both",
     abnormal:"Should be NORMAL in isolated CTS — abnormal ulnar suggests polyneuropathy",col:NAVY},
    {n:"4",title:"Internal Comparison Studies  (See next slide)",
     stim:"Palm (8 cm from wrist) for palmar mixed  |  Wrist for ring-finger/thumb studies",
     rec:"Wrist recording for palmar  |  Digit IV / Thumb for sensory comparisons",
     measure:"Median vs Ulnar latency difference at equal distances",
     abnormal:"Median > Ulnar by > 0.3–0.4 ms  →  CTS confirmed even on background of DPN",col:GOLD},
  ];

  steps.forEach((st,i)=>{
    const y = 0.86 + i*1.13;
    // full row bg
    s.addShape(pres.ShapeType.rect,{x:0.28,y,w:9.44,h:1.0,
      fill:{color:WHITE},line:{color:LGRAY},
      shadow:{type:"outer",color:"000000",blur:3,offset:1,angle:135,opacity:0.07}});
    // step color panel
    s.addShape(pres.ShapeType.rect,{x:0.28,y,w:0.9,h:1.0,
      fill:{color:st.col},line:{color:st.col}});
    s.addText("STEP",{x:0.28,y:y+0.06,w:0.9,h:0.28,margin:0,
      fontSize:8,bold:true,color:st.col===GOLD?CHAR:WHITE,align:"center",fontFace:"Calibri"});
    s.addText(st.n,{x:0.28,y:y+0.3,w:0.9,h:0.45,margin:0,
      fontSize:24,bold:true,color:st.col===GOLD?CHAR:WHITE,align:"center",valign:"top",fontFace:"Calibri"});
    // content
    s.addText(st.title,{x:1.28,y:y+0.06,w:8.3,h:0.3,
      fontSize:13,bold:true,color:NAVY,fontFace:"Calibri"});
    s.addText("Stim: "+st.stim+"   |   Rec: "+st.rec,{x:1.28,y:y+0.36,w:8.3,h:0.24,
      fontSize:10,color:SLATE,fontFace:"Calibri"});
    s.addText("⚠ Abnormal: "+st.abnormal,{x:1.28,y:y+0.62,w:8.3,h:0.3,
      fontSize:10.5,bold:true,color:RED,fontFace:"Calibri"});
  });
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 6  INTERNAL COMPARISON STUDIES
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  s.background = {color:OFFWH};
  topBar(s, TEAL, "Internal Comparison Studies — Most Sensitive NCS Methods");
  tag(s, "COMPARISON");

  s.addText("Both median and ulnar nerves travel through the same forearm, so comparing their latencies at equal distances eliminates background polyneuropathy effects (e.g. diabetic neuropathy)", {
    x:0.3,y:0.82,w:9.4,h:0.42,
    fontSize:11,italic:true,color:SLATE,fontFace:"Calibri"
  });

  const trows = [
    ["Study","Technique","Type","Abnormal Criterion","Usefulness"],
    ["Median–Ulnar\nPalmar Mixed","Stimulate palm (8 cm)\nRecord at wrist for both","Orthodromic\nmixed nerve","Median > Ulnar\nby > 0.3 ms","Most sensitive;\nbest first-line"],
    ["Median–Ulnar\nRing Finger","Stim wrist; record at\nDigit IV antidromically","Antidromic\nsensory","Median > Ulnar\nby > 0.4 ms","Useful when\npalmar normal"],
    ["Median–Ulnar\nLumbrical–Interossei","Stim wrist; record at\n2nd interosseous space","Motor\ncomparison","Median > Ulnar\nby > 0.4–0.5 ms","Best for\nmotor CTS"],
    ["Median–Radial\nSensory to Thumb","Stim median & radial\nat wrist; record at thumb","Antidromic\nsensory","Median > Radial\nby > 0.5 ms","Best when DPN\nis severe"],
  ];

  s.addTable(trows.map((row,ri)=>row.map((cell,ci)=>({
    text:cell,
    options:{
      fontSize:10.5, bold:ri===0||(ri>0&&ci===3),
      color:ri===0?WHITE:(ci===3?RED:CHAR),
      fill:ri===0?NAVY:(ri%2===0?WHITE:OFFWH),
      align:"center",valign:"middle",
      border:{pt:0.6,color:"C5D5E0"}, fontFace:"Calibri"
    }
  }))),{x:0.3,y:1.32,w:9.4,h:3.65,rowH:0.73,colW:[1.65,2.3,1.45,1.75,1.75]});

  // footnote + key rule
  s.addText("Source: Bradley & Daroff's Neurology in Clinical Practice, Table 106.4, p. 2636", {
    x:0.3,y:5.04,w:6,h:0.28,
    fontSize:9,italic:true,color:SLATE,fontFace:"Calibri"
  });
  box(s,0.3,5.3,9.4,0.2,GOLD,GOLD);
  s.addText("⭐  Rule: If Median latency exceeds Ulnar by the criterion value at equal distance → CTS is present, even if absolute latency is within 'normal' range due to background neuropathy", {
    x:0.4,y:5.3,w:9.2,h:0.2,margin:0,
    fontSize:9.5,bold:true,color:CHAR,align:"center",valign:"middle",fontFace:"Calibri"
  });
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 7  INCHING TECHNIQUE
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  s.background = {color:OFFWH};
  topBar(s, NAVY, "The Inching (Segmental Stimulation) Technique");
  tag(s, "INCHING");

  // Left — principle
  box(s, 0.28, 0.83, 4.65, 4.15, WHITE, TEAL);
  s.addText("Principle", {x:0.42,y:0.88,w:4.4,h:0.38,
    fontSize:15,bold:true,color:TEAL,fontFace:"Calibri"});
  s.addText([
    {text:"• Stimulate median nerve in ",options:{}},
    {text:"1-cm increments",options:{bold:true,color:TEAL}},
    {text:" across the wrist\n\n",options:{}},
    {text:"• Normal response: ",options:{bold:true}},
    {text:"latency increases linearly by ~0.16–0.21 ms per cm\n\n",options:{}},
    {text:"• Pathological: ",options:{bold:true,color:RED}},
    {text:"abrupt latency jump > 0.5 ms over a single 1-cm segment → focal lesion\n\n",options:{color:RED}},
    {text:"• Reference point (0): ",options:{bold:true}},
    {text:"distal wrist crease = origin of the transverse carpal ligament\n\n",options:{}},
    {text:"• SNAPs recorded from Digit II\n","CMAPs recorded from APB",options:{}},
  ],{x:0.42,y:1.3,w:4.35,h:3.5,
    fontSize:11.5,color:CHAR,fontFace:"Calibri",valign:"top"});

  // Right — why it's superior
  box(s, 5.1, 0.83, 4.65, 2.0, WHITE, TEAL2);
  s.addText("Why Inching is Superior to Routine NCS", {x:5.24,y:0.88,w:4.4,h:0.38,
    fontSize:13,bold:true,color:NAVY,fontFace:"Calibri"});
  s.addText([
    {text:"Over a 10-cm segment: ",options:{bold:true}},
    {text:"0.2 ms slowing = 10% change → easily MISSED\n\n",options:{color:SLATE}},
    {text:"Over a 1-cm segment: ",options:{bold:true}},
    {text:"0.2 ms slowing = 100% change → UNMISTAKABLE",options:{color:RED,bold:true}},
  ],{x:5.24,y:1.3,w:4.35,h:1.4,
    fontSize:11,color:CHAR,fontFace:"Calibri",valign:"top"});

  // Right — CTS findings box
  box(s, 5.1, 2.93, 4.65, 2.05, "EBF5FB", TEAL);
  s.addText("CTS Pattern on Inching", {x:5.24,y:2.98,w:4.4,h:0.35,
    fontSize:13,bold:true,color:TEAL,fontFace:"Calibri"});
  s.addText([
    {text:"Normal subject: ",options:{bold:true,color:GREEN}},
    {text:"uniform ~0.16–0.21 ms/cm increase throughout\n\n",options:{}},
    {text:"CTS patient: ",options:{bold:true,color:RED}},
    {text:"abrupt jump (>0.5 ms) at a single level, usually at or just distal to the distal wrist crease (transverse carpal ligament)\n\n",options:{}},
    {text:"Waveform change ",options:{bold:true}},
    {text:"(amplitude drop, shape change) accompanies the latency jump",options:{}},
  ],{x:5.24,y:3.36,w:4.35,h:1.55,
    fontSize:10.5,color:CHAR,fontFace:"Calibri",valign:"top"});
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 8  SEVERITY GRADING
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  s.background = {color:OFFWH};
  topBar(s, TEAL, "NCS Severity Grading in CTS");
  tag(s, "GRADING");

  const grades = [
    {grade:"MILD",   col:GREEN,  bg:"E8F5E9",
     f:["Prolonged median sensory latency / slowed SCV only",
        "Motor distal latency: NORMAL",
        "CMAP amplitude: NORMAL",
        "No denervation on EMG"],
     rx:"Splints in neutral + NSAID / Corticosteroid injection"},
    {grade:"MODERATE",col:ORANGE,bg:"FFF3E0",
     f:["Prolonged motor AND sensory distal latencies",
        "SNAP amplitude reduced (but present)",
        "CMAP amplitude mildly reduced",
        "No active denervation on EMG"],
     rx:"Steroid injection → Consider surgical release"},
    {grade:"SEVERE", col:RED,    bg:"FFEBEE",
     f:["Absent median SNAP",
        "Significantly prolonged motor latency",
        "Reduced CMAP amplitude (axonal loss)",
        "EMG: chronic neurogenic changes in APB"],
     rx:"Surgical carpal tunnel release (urgent)"},
    {grade:"EXTREME",col:PURPLE, bg:"F3E5F5",
     f:["Absent SNAP and absent/minimal CMAP",
        "Fibrillations + PSWs in APB (active denervation)",
        "Reduced/absent MUPs on voluntary activation",
        "EMG mandatory to quantify axonal loss"],
     rx:"Emergency surgical release — recovery guarded"},
  ];

  grades.forEach((g,i)=>{
    const col = i%2; const row = Math.floor(i/2);
    const x = 0.28 + col*4.84; const y = 0.84 + row*2.32;
    box(s,x,y,4.6,2.22,g.bg,g.col);
    // grade banner
    s.addShape(pres.ShapeType.rect,{x,y,w:4.6,h:0.46,fill:{color:g.col},line:{color:g.col}});
    s.addText(g.grade,{x,y,w:4.6,h:0.46,margin:0,
      fontSize:18,bold:true,color:WHITE,align:"center",valign:"middle",fontFace:"Calibri"});
    g.f.forEach((fi,ii)=>{
      s.addText("•  "+fi,{x:x+0.15,y:y+0.5+ii*0.3,w:4.3,h:0.28,
        fontSize:10,color:CHAR,fontFace:"Calibri"});
    });
    // rx band
    s.addShape(pres.ShapeType.rect,{x:x+0.1,y:y+1.78,w:4.4,h:0.32,
      fill:{color:g.col,transparency:65},line:{color:g.col}});
    s.addText("Rx: "+g.rx,{x:x+0.12,y:y+1.78,w:4.36,h:0.32,margin:0,
      fontSize:9.5,bold:true,color:CHAR,align:"center",valign:"middle",fontFace:"Calibri"});
  });
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 9  NORMAL VALUES TABLE
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  s.background = {color:OFFWH};
  topBar(s, NAVY, "Normal NCS Reference Values");
  tag(s, "NORMAL VALUES", TEAL);

  s.addText("Adams & Victor's Principles of Neurology, Table 2-5  (Mean ± 2SD, Adults 16–65 yr)", {
    x:0.3,y:0.82,w:9.4,h:0.3,
    fontSize:10,italic:true,color:SLATE,fontFace:"Calibri"
  });

  s.addText("MOTOR NCS",{x:0.3,y:1.17,w:2,h:0.3,
    fontSize:13,bold:true,color:TEAL,fontFace:"Calibri"});

  const mhdr = ["Nerve","Stimulate","Record","DML (ms)","Amp (mV)","CV (m/s)","F-wave (ms)"];
  const mdat = [
    ["Median","Wrist","APB","< 4.2","> 4.4","> 49","< 31"],
    ["Ulnar","Wrist","ADM","< 3.4","> 6.0","> 49","< 32"],
    ["Peroneal","Ankle","EDB","< 5.8","> 2.0","> 42","< 58"],
    ["Tibial","Ankle","AH","< 6.5","> 3.0","> 41","< 59"],
  ];
  s.addTable([mhdr,...mdat].map((row,ri)=>row.map((cell,ci)=>({
    text:cell, options:{
      fontSize:10.5, bold:ri===0,
      color:ri===0?WHITE:(ci>=3?TEAL:CHAR),
      fill:ri===0?NAVY:(ri%2===0?WHITE:OFFWH),
      align:"center",valign:"middle",
      border:{pt:0.5,color:"C5D5E0"},fontFace:"Calibri"
    }
  }))),{x:0.3,y:1.5,w:9.4,h:1.55,rowH:0.31,colW:[1.3,1.2,1.0,1.45,1.3,1.3,1.45]});

  s.addText("SENSORY NCS",{x:0.3,y:3.12,w:2.2,h:0.3,
    fontSize:13,bold:true,color:TEAL2,fontFace:"Calibri"});

  const shdr = ["Nerve","Stimulate","Record","Onset (ms)","Peak (ms)","Amp (µV)","CV (m/s)"];
  const sdat = [
    ["Median","Wrist","Digit II","< 3.5","< 3.6","> 20","> 50"],
    ["Ulnar","Wrist","Digit V","< 3.1","< 3.2","> 17","> 50"],
    ["Sural","Calf","Ankle","< 4.4","–","> 6","> 40"],
    ["Radial","Forearm","Thumb","< 2.9","–","> 15","> 50"],
  ];
  s.addTable([shdr,...sdat].map((row,ri)=>row.map((cell,ci)=>({
    text:cell, options:{
      fontSize:10.5, bold:ri===0,
      color:ri===0?WHITE:(ci>=3?TEAL2:CHAR),
      fill:ri===0?TEAL:(ri%2===0?WHITE:OFFWH),
      align:"center",valign:"middle",
      border:{pt:0.5,color:"C5D5E0"},fontFace:"Calibri"
    }
  }))),{x:0.3,y:3.45,w:9.4,h:1.55,rowH:0.31,colW:[1.3,1.2,1.0,1.45,1.3,1.3,1.45]});

  // CTS highlight
  box(s,0.3,5.07,9.4,0.35,"FFF8E1",GOLD);
  s.addText("CTS cut-offs: Median motor DML > 4.2 ms  |  Median sensory onset > 3.5 ms  |  SNAP amplitude < 20 µV  →  Pathological", {
    x:0.42,y:5.07,w:9.2,h:0.35,margin:0,
    fontSize:11.5,bold:true,color:CHAR,align:"center",valign:"middle",fontFace:"Calibri"
  });
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 10  CTS IN DIABETES — CHALLENGES
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  s.background = {color:NAVY};
  s.addShape(pres.ShapeType.rect,{x:0,y:0,w:10,h:0.72,fill:{color:RED},line:{color:RED}});
  s.addText("CTS in Diabetic Patients — The Diagnostic Challenge",{
    x:0.35,y:0,w:9.3,h:0.72,margin:0,
    fontSize:21,bold:true,color:WHITE,valign:"middle",fontFace:"Calibri"});
  tag(s,"DM + CTS",WHITE);

  const chal = [
    {n:"1",title:"Problem: Elevated Baselines (Background DPN)",col:RED,
     body:"Diabetic peripheral neuropathy (DPN) prolongs latencies and reduces amplitudes across ALL nerves. A median DML of 4.8 ms looks like 'mild CTS' when the ulnar is also 4.5 ms — this pattern reflects diffuse neuropathy, NOT focal entrapment. Absolute values alone are unreliable in DM."},
    {n:"2",title:"Problem: DM is an Independent CTS Risk Factor",col:GOLD,
     body:"Diabetics have 2–3× higher CTS prevalence than the general population. Mechanisms include: metabolic accumulation within the flexor tendons, tenosynovitis, microangiopathy of the vasa nervorum, and increased susceptibility of already-compromised nerves to compressive injury ('double crush' phenomenon)."},
    {n:"3",title:"Problem: Small Fiber DPN — NCS May Be Normal",col:TEAL2,
     body:"NCS only captures large myelinated fibres (A-alpha / A-beta). In DM, early and predominant small fibre (C and A-delta) involvement gives NORMAL NCS despite severe burning pain, autonomic dysfunction, and reduced IENFD on skin biopsy. Skin biopsy or QSART is needed for diagnosis in these patients."},
  ];

  chal.forEach((c,i)=>{
    const y = 0.86 + i*1.48;
    s.addShape(pres.ShapeType.rect,{x:0.28,y,w:9.44,h:1.35,
      fill:{color:"0D2849"},line:{color:c.col}});
    s.addShape(pres.ShapeType.rect,{x:0.28,y,w:0.55,h:1.35,fill:{color:c.col},line:{color:c.col}});
    s.addText(c.n,{x:0.28,y,w:0.55,h:1.35,margin:0,
      fontSize:28,bold:true,color:c.col===GOLD?CHAR:WHITE,align:"center",valign:"middle",fontFace:"Calibri"});
    s.addText(c.title,{x:0.95,y:y+0.08,w:8.6,h:0.32,
      fontSize:13,bold:true,color:c.col===GOLD?GOLD:c.col,fontFace:"Calibri"});
    s.addText(c.body,{x:0.95,y:y+0.44,w:8.6,h:0.82,
      fontSize:10.5,color:"B0C4D8",fontFace:"Calibri",valign:"top"});
  });

  s.addShape(pres.ShapeType.rect,{x:0.28,y:5.32,w:9.44,h:0.2,fill:{color:TEAL},line:{color:TEAL}});
  s.addText("Solution: Internal Comparison Studies (next slide) isolate the focal CTS component from background DPN", {
    x:0.38,y:5.32,w:9.2,h:0.2,margin:0,
    fontSize:10,bold:true,color:WHITE,align:"center",valign:"middle",fontFace:"Calibri"});
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 11  DM+CTS PROTOCOL + DISTINGUISHING TABLE
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  s.background = {color:OFFWH};
  topBar(s, TEAL, "NCS Protocol: CTS Superimposed on Diabetic Neuropathy");
  tag(s,"DM PROTOCOL");

  // Left column — steps
  s.addText("Step-by-Step Protocol", {x:0.28,y:0.84,w:5.5,h:0.32,
    fontSize:14,bold:true,color:NAVY,fontFace:"Calibri"});

  const steps = [
    "Ensure skin temperature > 32°C  — cold falsely prolongs latency; critical in DM",
    "Median motor NCS (wrist → APB)  +  Ulnar motor NCS (comparator)",
    "Median sensory NCS antidromic (wrist → Digit II)",
    "Median–Ulnar palmar mixed comparison  (most sensitive single test)",
    "Median–Radial sensory to thumb comparison  (best when DPN is severe)",
    "Sural + Peroneal NCS  — grade severity of background DPN (lower limb worse)",
    "Needle EMG of APB if moderate–severe CTS: fibrillations = axonal loss = surgical urgency",
  ];
  steps.forEach((st,i)=>{
    const y = 1.22 + i*0.57;
    circle(s, 0.28, y+0.06, 0.38, TEAL, String(i+1));
    s.addText(st,{x:0.75,y,w:5.15,h:0.5,
      fontSize:10,color:CHAR,fontFace:"Calibri",valign:"middle"});
  });

  // Right column — distinguishing table
  s.addText("Focal CTS vs Diffuse DPN",{x:6.15,y:0.84,w:3.7,h:0.32,
    fontSize:13,bold:true,color:NAVY,fontFace:"Calibri"});

  const drows = [
    ["Feature","Focal CTS","Diffuse DPN"],
    ["Sensory latency","Median > Ulnar","Both equal"],
    ["Motor latency","DML only prolonged;\nforearm MCV normal","All segments\nslowed"],
    ["Upper vs Lower","Upper limb\nisolated","Lower limb\nworse"],
    ["Sural nerve","Normal","Abnormal/absent\nSNAP"],
    ["F-waves","Normal","All prolonged"],
  ];
  s.addTable(drows.map((row,ri)=>row.map((cell,ci)=>({
    text:cell, options:{
      fontSize:9.5, bold:ri===0||ci===0,
      color:ri===0?WHITE:(ci===1?TEAL:(ci===2?RED:CHAR)),
      fill:ri===0?NAVY:(ri%2===0?WHITE:OFFWH),
      align:"center",valign:"middle",
      border:{pt:0.5,color:"C5D5E0"},fontFace:"Calibri"
    }
  }))),{x:6.15,y:1.22,w:3.7,h:3.65,rowH:0.61,colW:[1.3,1.2,1.2]});
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 12  DIAGNOSIS FLOWCHART
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  s.background = {color:OFFWH};
  topBar(s, NAVY, "Diagnostic Flowchart — CTS in the Diabetic Patient");
  tag(s, "FLOWCHART");

  // ── boxes ──
  function fbox(x,y,w,h,fill,border,text,tcolor,fs,bold){
    s.addShape(pres.ShapeType.rect,{x,y,w,h,fill:{color:fill},line:{color:border||fill},
      shadow:{type:"outer",color:"000000",blur:4,offset:2,angle:135,opacity:0.1}});
    s.addText(text,{x,y,w,h,margin:0,
      fontSize:fs||11,bold:bold!==false,color:tcolor||WHITE,
      align:"center",valign:"middle",fontFace:"Calibri"});
  }
  function arr(x,y,len,horiz){
    if(horiz){
      s.addShape(pres.ShapeType.rect,{x,y:y+0.05,w:len,h:0.08,fill:{color:SLATE},line:{color:SLATE}});
      s.addShape(pres.ShapeType.triangle,{x:x+len-0.12,y,w:0.18,h:0.18,fill:{color:SLATE},line:{color:SLATE}});
    } else {
      s.addShape(pres.ShapeType.rect,{x:x+0.05,y,w:0.08,h:len,fill:{color:SLATE},line:{color:SLATE}});
      s.addShape(pres.ShapeType.triangle,{x,y:y+len-0.1,w:0.18,h:0.18,fill:{color:SLATE},line:{color:SLATE}});
    }
  }

  // Top: suspected CTS
  fbox(3.2,0.88,3.6,0.52,NAVY,NAVY,"Suspected CTS in DM Patient",WHITE,12);
  arr(5.0,1.4,0.35,false);

  // NCS box
  fbox(2.0,1.75,6.0,0.72,TEAL,TEAL,
    "NCS: Median motor + sensory  |  Ulnar motor + sensory\nLower limb NCS (sural, peroneal, tibial)",WHITE,11);
  arr(5.0,2.47,0.32,false);

  // Decision diamond
  s.addShape(pres.ShapeType.rect,{x:2.8,y:2.79,w:4.4,h:0.62,
    fill:{color:"FFF8E1"},line:{color:GOLD,width:2}});
  s.addText("Are ALL nerves equally slowed?\n(length-dependent pattern, lower limbs worse?)",{
    x:2.8,y:2.79,w:4.4,h:0.62,margin:0,
    fontSize:11,bold:true,color:CHAR,align:"center",valign:"middle",fontFace:"Calibri"});

  // YES branch (left)
  arr(2.8,3.1,0.38,true); // horiz left
  s.addShape(pres.ShapeType.rect,{x:0.28,y:3.04,w:2.48,h:0.15,fill:{color:SLATE},line:{color:SLATE}});
  arr(1.42,3.19,0.32,false);
  fbox(0.28,3.51,2.9,0.54,ORANGE,ORANGE,"YES → Diffuse DPN\nconfirmed",WHITE,10.5);
  arr(1.73,4.05,0.32,false);
  fbox(0.28,4.37,2.9,0.62,SLATE,SLATE,
    "Consider skin biopsy\n(IENFD) or QSART\nfor small-fiber DPN",WHITE,10,true);

  // NO branch (right)
  arr(7.2,3.1,0.52,true);
  fbox(7.2,3.04,2.52,0.15,SLATE,SLATE,"",SLATE,1);
  arr(8.46,3.19,0.32,false);
  fbox(7.1,3.51,2.62,0.54,TEAL,TEAL,"NO → Median > Ulnar\nRun internal comparisons",WHITE,10.5);
  arr(8.41,4.05,0.32,false);
  fbox(7.1,4.37,2.62,0.62,GREEN,GREEN,
    "Median > Ulnar > 0.3 ms\n(palmar mixed)\n→ CTS CONFIRMED",WHITE,10,true);

  // Bottom: treatment
  arr(5.0,4.4,0.35,false);
  fbox(2.85,4.75,4.3,0.65,NAVY,NAVY,
    "Grade severity (Mild/Moderate/Severe)\nTreat accordingly: splint / steroid / surgery",WHITE,11);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 13  KEY EXAM POINTS
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  s.background = {color:NAVY};
  s.addShape(pres.ShapeType.rect,{x:0,y:0,w:10,h:0.72,fill:{color:GOLD},line:{color:GOLD}});
  s.addText("High-Yield Exam Points — DM Neurology",{
    x:0.35,y:0,w:9.3,h:0.72,margin:0,
    fontSize:22,bold:true,color:CHAR,valign:"middle",fontFace:"Calibri"});

  const pts = [
    {n:"1",t:"Sensory NCS is MORE SENSITIVE than motor in early CTS — prolonged median sensory latency is the FIRST NCS abnormality",col:GOLD},
    {n:"2",t:"Internal comparison (Median > Ulnar by >0.3 ms palmar mixed) is the MOST SENSITIVE method — MANDATORY when DPN coexists",col:TEAL2},
    {n:"3",t:"Inching technique: normal = 0.16–0.21 ms/cm; pathological = abrupt jump >0.5 ms over a single 1-cm segment at the carpal ligament",col:TEAL},
    {n:"4",t:"In DM + CTS: use Median–Ulnar palmar comparison AND Median–Radial thumb comparison to isolate the focal component from DPN",col:GOLD},
    {n:"5",t:"Temperature MUST be >32°C before NCS — DM patients have cold extremities that falsely prolong latencies and mimic neuropathy",col:TEAL2},
    {n:"6",t:"Needle EMG of APB in moderate–severe CTS: fibrillations + reduced MUP recruitment = axonal loss → surgical urgency",col:TEAL},
    {n:"7",t:"Post-surgical recovery: sensory SYMPTOMS improve first; NCS latency normalisation lags by months — do not re-test too early",col:GOLD},
  ];

  pts.forEach((p,i)=>{
    const y = 0.85 + i*0.66;
    s.addShape(pres.ShapeType.rect,{x:0.28,y,w:9.44,h:0.58,
      fill:{color:"0D2849"},line:{color:p.col}});
    s.addShape(pres.ShapeType.rect,{x:0.28,y,w:0.5,h:0.58,fill:{color:p.col},line:{color:p.col}});
    s.addText(p.n,{x:0.28,y,w:0.5,h:0.58,margin:0,
      fontSize:18,bold:true,color:p.col===GOLD?CHAR:WHITE,
      align:"center",valign:"middle",fontFace:"Calibri"});
    s.addText(p.t,{x:0.88,y:y+0.06,w:8.7,h:0.46,
      fontSize:11,color:WHITE,fontFace:"Calibri",valign:"middle"});
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// ════════════════════════════════════════════════════════════════════════════
// SLIDE 14  THANK YOU / REFERENCES
// ════════════════════════════════════════════════════════════════════════════
{
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  s.background = {color:NAVY};
  s.addShape(pres.ShapeType.rect,{x:0,y:0,w:0.45,h:5.625,fill:{color:TEAL},line:{color:TEAL}});
  s.addShape(pres.ShapeType.rect,{x:0.45,y:0,w:0.07,h:5.625,fill:{color:GOLD},line:{color:GOLD}});

  s.addText("Thank You",{x:0.75,y:0.7,w:9,h:1.0,
    fontSize:46,bold:true,color:WHITE,fontFace:"Calibri",align:"left"});
  s.addShape(pres.ShapeType.rect,{x:0.75,y:1.74,w:5,h:0.055,fill:{color:GOLD},line:{color:GOLD}});

  s.addText("References",{x:0.75,y:1.96,w:9,h:0.35,
    fontSize:17,bold:true,color:TEAL2,fontFace:"Calibri"});

  const refs = [
    "1.  Bradley WG, Daroff RB et al. Bradley and Daroff's Neurology in Clinical Practice, 8th Ed. — Chapter 36 (EMG/NCS) & Chapter 106 (Entrapment Neuropathies)",
    "2.  Adams RD, Victor M, Ropper AH. Adams and Victor's Principles of Neurology, 12th Ed. — Chapter 2 (Electrophysiologic Studies, Table 2-5)",
    "3.  Kimura J. The carpal tunnel syndrome: localization of conduction abnormalities within the distal segment of the median nerve. Brain 1979;102:619–635",
    "4.  American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM). Practice Guidelines for CTS Electrodiagnosis",
    "5.  Campbell's Operative Orthopaedics, 15th Ed. 2026 — Carpal Tunnel Syndrome (NCS in surgical planning)",
  ];
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    s.addText(r,{x:0.75,y:2.38+i*0.52,w:9.0,h:0.44,
      fontSize:10,color:"7B9EC4",fontFace:"Calibri"});
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  s.addText("DM Neurology — Electrophysiology Seminar",{
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    fontSize:12,italic:true,color:WHITE,align:"center",valign:"middle",fontFace:"Calibri"});
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// ── WRITE ────────────────────────────────────────────────────────────────────
pres.writeFile({fileName:"/home/daytona/workspace/NCS_CTS_DM_v2.pptx"})
  .then(()=>{ console.log("DONE"); })
  .catch(e=>{ console.error("FAIL",e); process.exit(1); });

Successfully replaced 1 instance(s) of the string in '/home/daytona/workspace/ncs-cts-ppt/build2.js'