Orris

Features of contralateral and ipsilateral hemiplegia

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corticospinal tract pyramidal decussation hemiplegia diagram

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Here is a comprehensive breakdown of contralateral vs. ipsilateral hemiplegia, covering the anatomical basis, clinical features, and specific syndromes.

Contralateral vs. Ipsilateral Hemiplegia

Anatomical Basis

The corticospinal (pyramidal) tract decussates at the lower medulla (pyramidal decussation). This single anatomical fact determines which side of the body is weak when the tract is damaged:
  • Above the decussation (cerebral cortex, corona radiata, internal capsule, midbrain, upper pons, lower pons down to the upper medulla) - the lesion produces contralateral hemiplegia.
  • Below the decussation (cervical spinal cord) - the lesion produces ipsilateral hemiplegia.

CONTRALATERAL HEMIPLEGIA

This is by far the most frequent form of hemiplegia.

General Features (UMN pattern)

All contralateral hemiplegias share upper motor neuron (UMN) features on the affected side:
  • Weakness/paralysis of the face, arm, and leg on the opposite side of the lesion
  • Spasticity (clasp-knife rigidity) - develops after initial flaccid phase
  • Hyperreflexia (exaggerated deep tendon reflexes)
  • Babinski sign (extensor plantar response)
  • No significant muscle atrophy (unless disuse, or if anterior horn cells are also damaged at the cord level)
  • Hemiplegic gait (circumduction of the leg)

By Level of Lesion

LocationWeakness PatternDistinguishing Features
Cerebral cortexContralateral face + arm + leg (all together only if extensive)Focal deficits possible (just leg or arm/face); seizures; aphasia (dominant hemisphere); anosognosia; homonymous hemianopia; astereognosis
Internal capsuleContralateral face + arm + leg (dense, all equal)"Pure motor hemiplegia" (capsular lacune); no cortical signs
MidbrainContralateral arm + leg + lower faceWeber syndrome: ipsilateral CN III palsy + contralateral hemiplegia (crossed!)
Upper ponsContralateral arm + leg + lower faceAssociated CN V, VI, VII palsies ipsilateral
Lower ponsContralateral arm + legMillard-Gubler syndrome: ipsilateral CN VI + VII palsy + contralateral hemiplegia
Medulla (medial)Contralateral arm + leg, spares faceDejerine (medial medullary) syndrome: ipsilateral tongue weakness + contralateral hemiplegia + contralateral hemisensory loss

IPSILATERAL HEMIPLEGIA

Less common; occurs in two main situations:

1. Cervical Spinal Cord Lesion (below decussation)

  • Ipsilateral hemiplegia (corticospinal tract already crossed)
  • Spares the face entirely
  • UMN signs below the level of the lesion on the ipsilateral side
  • Brown-Sequard syndrome (cord hemisection): ipsilateral hemiplegia + ipsilateral loss of vibration and proprioception (posterior column) + contralateral loss of pain and temperature (spinothalamic tract)

2. Kernohan's Phenomenon (False Localizing Sign)

  • Caused by transtentorial (uncal) herniation
  • The herniated uncus pushes the midbrain so far contralaterally that the opposite cerebral peduncle is compressed against the tentorial notch
  • This damages the contralateral (to the original lesion) corticospinal tract - producing hemiplegia on the same side as the original lesion (ipsilateral)
  • This is a "false localizing sign" - the hemiplegia incorrectly suggests a lesion on the same side as the brain mass

Crossed (Alternating) Hemiplegia - The Brainstem Signature

Crossed syndromes produce:
  • Ipsilateral cranial nerve palsy (at the level of the lesion)
  • Contralateral hemiplegia (corticospinal tract involvement below the cranial nerve nucleus)
This combination unambiguously localizes a lesion to the brainstem.
SyndromeLevelIpsilateral CNContralateral Body
WeberMidbrainCN III palsy (ptosis, fixed dilated pupil, down-and-out eye)Hemiplegia
ClaudeMidbrain tegmentumCN III palsy + ataxiaHemiplegia
Millard-GublerLower ponsCN VI + VII palsyHemiplegia
FovillePonsCN VI + ipsilateral conjugate gaze palsy + CN VIIContralateral hemiplegia
Dejerine (medial medullary)MedullaHypoglossal (CN XII) tongue weaknessHemiplegia + hemisensory loss
RaymondPonsCN VI palsyContralateral hemiplegia

Quick Summary Table

TypeSide of Lesion vs. WeaknessLevelKey Clue
Contralateral (cortex/capsule)OppositeSupratentorialCortical signs, aphasia, seizures
Contralateral (brainstem)Opposite body, same-side CN palsyBrainstemCrossed signs
Ipsilateral (cervical cord)Same side, no faceBelow decussationBrown-Sequard pattern
Ipsilateral (Kernohan's)Same side as massUncal herniationFalse localizing sign
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Brown Sequard syndrome

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Brown Sequard syndrome spinal cord hemisection diagram ipsilateral contralateral deficits

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Here is a comprehensive account of Brown-Séquard Syndrome from the textbook sources:

Brown-Séquard Syndrome (Spinal Cord Hemisection)

Definition

Brown-Séquard syndrome (BSS) results from damage to one lateral half of the spinal cord. It produces a characteristic dissociated pattern: motor deficits and one class of sensory loss on the same (ipsilateral) side as the lesion, and a different class of sensory loss on the opposite (contralateral) side.

Anatomical Basis

Three major cord tracts are disrupted by hemisection:
TractLocation in cordCrosses atEffect of hemisection
Lateral corticospinal tractLateral funiculus (ipsilateral)Already crossed at pyramidal decussationIpsilateral UMN weakness below lesion
Posterior (dorsal) columnsPosterior funiculus (ipsilateral)Crosses in medulla (nucleus gracilis/cuneatus)Ipsilateral loss of proprioception, vibration, 2-point discrimination, tactile localization
Spinothalamic tract (anterolateral system)Anterior/lateral funiculus (contralateral - already crossed)Crosses at the same spinal cord level (ventral commissure), 2-3 segments above entryContralateral loss of pain and temperature, 2-6 segments below lesion

Classic Clinical Features

IPSILATERAL (same side as lesion) - below the level:

  • UMN hemiplegia/hemiparesis: spasticity, hyperreflexia, Babinski sign
  • Loss of proprioception (joint position sense)
  • Loss of vibration sense
  • Loss of 2-point discrimination and tactile localization (fine/discriminative touch)
  • Loss of crude light touch partially (dorsal column contribution)

CONTRALATERAL (opposite side) - 1-2 dermatomes below the lesion:

  • Loss of pain sensation
  • Loss of temperature sensation
  • Crude touch is largely preserved (spinothalamic tract partially preserves it)

AT THE LEVEL of the lesion (ipsilateral):

  • LMN signs: flaccid weakness, wasting, areflexia (anterior horn damage)
  • Ipsilateral band of pain/temperature loss (1-2 segments) - from damage to the posterior horn cells before their axons have crossed
  • A narrow zone of hyperalgesia just above the lesion (irritation of dorsal root entry zone)

Important Nuances

  • The contralateral spinothalamic loss begins 1-2 dermatomes below the lesion (because the entering fibers ascend 2-3 segments before crossing in the ventral commissure)
  • Crude "light touch" is partially preserved bilaterally - it travels in both dorsal columns and spinothalamic tract; the intact contralateral spinothalamic tract compensates partially
  • At cervical levels (C8-T2): if the ciliospinal center of Budge is involved, there may be an ipsilateral Horner syndrome (ptosis, miosis, anhidrosis)

Causes

Traumatic (most common):
  • Penetrating injury (stab wounds) - most common overall cause
  • Blunt trauma (hyperextension > flexion injuries)
  • Herniated cervical disc (lateral)
  • Vertebral fracture-dislocation
Non-traumatic:
  • Multiple sclerosis (demyelinating plaques)
  • Spinal cord tumors (primary or metastatic) - lateral compression
  • Spinal cord ischemia / epidural hematoma
  • Spinal subdural hematoma
  • Hematomyelia
  • Posttraumatic or infectious arachnoiditis
  • Cervical manipulation
  • Spinal cord herniation
BSS accounts for 1-4% of all traumatic spinal cord injuries and occurs most frequently at the cervical spine.

Brown-Séquard Plus Syndrome

The pure classic presentation is rarely encountered in practice. More commonly, patients show Brown-Séquard plus (Taylor & Gleave, 1957):
  • Asymmetrical hemiplegia rather than complete unilateral paralysis
  • Hypoalgesia more prominent on the less paretic side
  • A mixed or incomplete pattern
Counter-intuitively, pure BSS carries a worse prognosis than BSS plus.

Prognosis

BSS has the best functional motor recovery among all incomplete spinal cord syndromes. Most patients:
  • Recover ambulatory function
  • Regain bowel and bladder continence
  • Those with more upper > lower extremity weakness have especially favorable ambulation outcomes

Comparison with Other Cord Syndromes

FeatureBrown-SéquardCentral CordAnterior Cord
Motor lossIpsilateral UMNArms > legs bilaterallyBilateral (UMN)
Pain/temp lossContralateralBilateral "suspended" (cape/vest)Bilateral below lesion
Proprioception/vibrationIpsilateral lossPreservedPreserved
CausePenetrating trauma, MSHyperextension in elderlyAnterior spinal artery infarct
Sources:

Simple diagram to explain Brown Sequard syndrome

Generating Image

A clean medical educational diagram explaining Brown-Séquard Syndrome (spinal cord hemisection). The diagram shows: 1. At the top: a cross-section of the spinal cord with the LEFT half shaded/lesioned (labeled "Lesion - Left hemisection"). Three tracts are labeled inside: "Lateral Corticospinal Tract (ipsilateral)", "Posterior Columns (ipsilateral)", and "Spinothalamic Tract (already crossed - contralateral)". 2. In the middle: a simple human body outline (front view), split down the middle, with color-coded deficit zones: - LEFT side of body: Red shading labeled "Ipsilateral (LEFT) side: UMN weakness (spasticity, hyperreflexia, Babinski), Loss of proprioception & vibration" - RIGHT side of body: Blue shading labeled "Contralateral (RIGHT) side: Loss of pain & temperature (1-2 dermatomes below lesion)" 3. At the level of lesion: a small yellow band across both sides labeled "At lesion level: LMN signs ipsilaterally + narrow band of ipsilateral pain/temp loss" 4. A small legend box in the corner: Red = Ipsilateral motor + dorsal column loss, Blue = Contralateral spinothalamic loss 5. Title at top: "Brown-Séquard Syndrome" with subtitle "Spinal Cord Hemisection" Clean white background, medical textbook style, clear labels, simple arrows showing tract pathways.

Brown-Séquard Syndrome Diagram
Here is a quick guide to reading the diagram:
  • Left half shaded = the side of the cord lesion
  • Red (left body) = ipsilateral deficits: UMN weakness (spasticity, hyperreflexia, Babinski) + loss of proprioception and vibration - because the corticospinal tract and posterior columns have already crossed above the cord
  • Blue (right body) = contralateral deficits: loss of pain and temperature, starting 1-2 dermatomes below the lesion - because the spinothalamic fibers cross within the cord before ascending
  • Yellow band = at the lesion level itself: a narrow ipsilateral strip of pain/temp loss (posterior horn damage before fibres cross) + LMN signs (anterior horn damage)
The key teaching point is the dissociation: motor loss and one type of sensory loss on the same side, a different sensory modality lost on the opposite side - all from a single unilateral cord lesion.

Create a downloadable PDF summary of Brown-Séquard Syndrome for reference

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Running Command

ls -la /tmp/workspace/ 2>/dev/null || mkdir -p /tmp/workspace && echo "workspace ready"

Running Command

mkdir -p /tmp/workspace/bss-pdf && python3 << 'EOF' from reportlab.lib.pagesizes import A4 from reportlab.lib import colors from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle from reportlab.lib.units import cm, mm from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle, HRFlowable, KeepTogether from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_JUSTIFY from reportlab.platypus import Image import urllib.request, os # Download the diagram image img_url = "https://cdn.orris.care/image-gen/d72a506e8ccb4f67a9d37049f9922a8a.png" img_path = "/tmp/workspace/bss-pdf/bss_diagram.png" urllib.request.urlretrieve(img_url, img_path) print("Image downloaded:", os.path.exists(img_path)) EOF

Writing File

~/bss-pdf/generate_bss_pdf.py

from reportlab.lib.pagesizes import A4
from reportlab.lib import colors
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.units import cm, mm
from reportlab.platypus import (SimpleDocTemplate, Paragraph, Spacer, Table,
                                 TableStyle, HRFlowable, KeepTogether, Image)
from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_JUSTIFY
from reportlab.pdfbase import pdfmetrics
from reportlab.pdfbase.ttfonts import TTFont

OUTPUT = "/tmp/workspace/bss-pdf/Brown_Sequard_Syndrome.pdf"
IMG_PATH = "/tmp/workspace/bss-pdf/bss_diagram.png"

# ── Colours ──────────────────────────────────────────────────────────────────
NAVY    = colors.HexColor("#1a3a5c")
TEAL    = colors.HexColor("#0f7173")
RED     = colors.HexColor("#c0392b")
BLUE    = colors.HexColor("#2471a3")
ORANGE  = colors.HexColor("#d35400")
LBLUE   = colors.HexColor("#d6eaf8")
LRED    = colors.HexColor("#fadbd8")
LYELLOW = colors.HexColor("#fef9e7")
LGREY   = colors.HexColor("#f2f3f4")
WHITE   = colors.white
BLACK   = colors.black

doc = SimpleDocTemplate(
    OUTPUT,
    pagesize=A4,
    leftMargin=1.8*cm, rightMargin=1.8*cm,
    topMargin=1.5*cm,  bottomMargin=1.8*cm,
    title="Brown-Séquard Syndrome – Clinical Reference",
    author="Orris Medical AI"
)

W, H = A4
CW = W - 3.6*cm   # content width

styles = getSampleStyleSheet()

# ── Custom styles ─────────────────────────────────────────────────────────────
def S(name, **kw):
    return ParagraphStyle(name, **kw)

title_style = S("Title2", fontSize=20, textColor=WHITE,
                alignment=TA_CENTER, fontName="Helvetica-Bold",
                spaceAfter=2, leading=24)
subtitle_style = S("Sub", fontSize=11, textColor=colors.HexColor("#d0e8f5"),
                   alignment=TA_CENTER, fontName="Helvetica", spaceAfter=0)

h1 = S("H1", fontSize=13, textColor=WHITE, fontName="Helvetica-Bold",
        spaceAfter=3, leading=16, leftIndent=6)
h2 = S("H2", fontSize=11, textColor=NAVY, fontName="Helvetica-Bold",
        spaceBefore=8, spaceAfter=3, leading=14)
body = S("Body2", fontSize=9.5, textColor=BLACK, fontName="Helvetica",
          leading=14, spaceAfter=3, alignment=TA_JUSTIFY)
bullet = S("Bullet2", fontSize=9.5, textColor=BLACK, fontName="Helvetica",
            leading=14, spaceAfter=2, leftIndent=14, firstLineIndent=-10)
small = S("Small", fontSize=8.5, textColor=colors.HexColor("#555555"),
           fontName="Helvetica-Oblique", leading=12, alignment=TA_CENTER)
note_style = S("Note", fontSize=8.5, textColor=colors.HexColor("#444444"),
               fontName="Helvetica-Oblique", leading=12, spaceAfter=2)

def bull(text, color=BLACK):
    return Paragraph(f"• {text}", bullet)

def section_header(title, bg=TEAL):
    data = [[Paragraph(title, h1)]]
    t = Table(data, colWidths=[CW])
    t.setStyle(TableStyle([
        ("BACKGROUND", (0,0), (-1,-1), bg),
        ("TOPPADDING",    (0,0), (-1,-1), 5),
        ("BOTTOMPADDING", (0,0), (-1,-1), 5),
        ("LEFTPADDING",   (0,0), (-1,-1), 8),
        ("ROUNDEDCORNERS", [4]),
    ]))
    return t

# ── Build story ───────────────────────────────────────────────────────────────
story = []

# ── Title block ───────────────────────────────────────────────────────────────
title_data = [[Paragraph("Brown-Séquard Syndrome", title_style)],
              [Paragraph("Spinal Cord Hemisection  |  Clinical Reference Summary", subtitle_style)]]
title_tbl = Table(title_data, colWidths=[CW])
title_tbl.setStyle(TableStyle([
    ("BACKGROUND", (0,0), (-1,-1), NAVY),
    ("TOPPADDING",    (0,0), (-1,-1), 12),
    ("BOTTOMPADDING", (0,0), (-1,-1), 12),
    ("ROUNDEDCORNERS", [6]),
]))
story.append(title_tbl)
story.append(Spacer(1, 10))

# ── Definition ────────────────────────────────────────────────────────────────
story.append(section_header("Definition"))
story.append(Spacer(1, 4))
story.append(Paragraph(
    "Brown-Séquard Syndrome (BSS) results from <b>hemisection (damage to one lateral half) of the "
    "spinal cord</b>. It produces a characteristic <b>dissociated sensorimotor deficit</b>: "
    "motor loss and one class of sensory loss <b>ipsilateral</b> to the lesion, "
    "and a different sensory modality lost <b>contralaterally</b>.",
    body))
story.append(Paragraph(
    "BSS accounts for <b>1–4%</b> of all traumatic spinal cord injuries and most commonly "
    "occurs at the <b>cervical spine</b>.",
    body))
story.append(Spacer(1, 6))

# ── Diagram ───────────────────────────────────────────────────────────────────
story.append(section_header("Diagram – Tract Deficits in BSS"))
story.append(Spacer(1, 4))
img = Image(IMG_PATH, width=CW*0.88, height=CW*0.62)
img.hAlign = "CENTER"
story.append(img)
story.append(Paragraph("Figure: Cross-section of cord (left hemisection) showing ipsilateral vs. contralateral deficits.", small))
story.append(Spacer(1, 6))

# ── Anatomical basis ──────────────────────────────────────────────────────────
story.append(section_header("Anatomical Basis – Three Key Tracts"))
story.append(Spacer(1, 4))

tract_data = [
    [Paragraph("<b>Tract</b>", S("th", fontSize=9, textColor=WHITE, fontName="Helvetica-Bold", leading=12)),
     Paragraph("<b>Location</b>", S("th", fontSize=9, textColor=WHITE, fontName="Helvetica-Bold", leading=12)),
     Paragraph("<b>Where it crosses</b>", S("th", fontSize=9, textColor=WHITE, fontName="Helvetica-Bold", leading=12)),
     Paragraph("<b>Deficit after hemisection</b>", S("th", fontSize=9, textColor=WHITE, fontName="Helvetica-Bold", leading=12))],
    [Paragraph("Lateral Corticospinal", S("tc", fontSize=8.5, fontName="Helvetica", leading=12)),
     Paragraph("Lateral funiculus (ipsilateral)", S("tc", fontSize=8.5, fontName="Helvetica", leading=12)),
     Paragraph("Pyramidal decussation (medulla) – already crossed", S("tc", fontSize=8.5, fontName="Helvetica", leading=12)),
     Paragraph("<b>Ipsilateral</b> UMN weakness", S("tc", fontSize=8.5, fontName="Helvetica-Bold", textColor=RED, leading=12))],
    [Paragraph("Posterior Columns", S("tc", fontSize=8.5, fontName="Helvetica", leading=12)),
     Paragraph("Posterior funiculus (ipsilateral)", S("tc", fontSize=8.5, fontName="Helvetica", leading=12)),
     Paragraph("Nucleus gracilis/cuneatus in medulla – already crossed", S("tc", fontSize=8.5, fontName="Helvetica", leading=12)),
     Paragraph("<b>Ipsilateral</b> loss of proprioception, vibration, 2-point discrimination", S("tc", fontSize=8.5, fontName="Helvetica-Bold", textColor=RED, leading=12))],
    [Paragraph("Spinothalamic Tract", S("tc", fontSize=8.5, fontName="Helvetica", leading=12)),
     Paragraph("Anterolateral funiculus (contralateral – already crossed)", S("tc", fontSize=8.5, fontName="Helvetica", leading=12)),
     Paragraph("Crosses within cord at same/adjacent level via ventral commissure", S("tc", fontSize=8.5, fontName="Helvetica", leading=12)),
     Paragraph("<b>Contralateral</b> loss of pain & temperature (1–2 dermatomes below)", S("tc", fontSize=8.5, fontName="Helvetica-Bold", textColor=BLUE, leading=12))],
]

col_w = [CW*0.18, CW*0.22, CW*0.32, CW*0.28]
tract_tbl = Table(tract_data, colWidths=col_w, repeatRows=1)
tract_tbl.setStyle(TableStyle([
    ("BACKGROUND",    (0,0), (-1,0), TEAL),
    ("BACKGROUND",    (0,1), (-1,1), LRED),
    ("BACKGROUND",    (0,2), (-1,2), LRED),
    ("BACKGROUND",    (0,3), (-1,3), LBLUE),
    ("GRID",          (0,0), (-1,-1), 0.4, colors.HexColor("#cccccc")),
    ("VALIGN",        (0,0), (-1,-1), "TOP"),
    ("TOPPADDING",    (0,0), (-1,-1), 5),
    ("BOTTOMPADDING", (0,0), (-1,-1), 5),
    ("LEFTPADDING",   (0,0), (-1,-1), 5),
    ("RIGHTPADDING",  (0,0), (-1,-1), 5),
]))
story.append(tract_tbl)
story.append(Spacer(1, 6))

# ── Clinical features two-column ──────────────────────────────────────────────
story.append(section_header("Clinical Features"))
story.append(Spacer(1, 4))

ipsi_items = [
    "<b>UMN hemiplegia/hemiparesis</b> – spasticity, hyperreflexia, Babinski sign",
    "Loss of <b>proprioception</b> (joint position sense)",
    "Loss of <b>vibration sense</b>",
    "Loss of <b>2-point discrimination</b> and tactile localisation",
    "Partial loss of crude light touch",
    "(At C8–T2) <b>Ipsilateral Horner syndrome</b> – ptosis, miosis, anhidrosis",
]
contra_items = [
    "Loss of <b>pain sensation</b>",
    "Loss of <b>temperature sensation</b>",
    "Onset <b>1–2 dermatomes below</b> the lesion level",
    "Crude touch largely <b>preserved</b>",
]
at_level_items = [
    "<b>LMN signs ipsilaterally</b> – flaccid weakness, wasting, areflexia (anterior horn)",
    "Narrow ipsilateral band of <b>pain/temp loss</b> (posterior horn damage before fibres cross)",
    "Zone of <b>hyperalgesia</b> just above lesion (dorsal root zone irritation)",
]

def feature_box(title, items, bg, tc):
    content = [Paragraph(f"<b>{title}</b>", S("bh", fontSize=9.5, textColor=WHITE,
                fontName="Helvetica-Bold", leading=13, alignment=TA_CENTER))]
    for i in items:
        content.append(Paragraph(f"• {i}", S("bi", fontSize=8.5, textColor=BLACK,
                        fontName="Helvetica", leading=13, leftIndent=6, spaceAfter=2)))
    tbl = Table([[c] for c in content], colWidths=[(CW-10)/2])
    tbl.setStyle(TableStyle([
        ("BACKGROUND", (0,0), (-1,0), tc),
        ("BACKGROUND", (0,1), (-1,-1), bg),
        ("TOPPADDING",    (0,0), (-1,-1), 5),
        ("BOTTOMPADDING", (0,0), (-1,-1), 4),
        ("LEFTPADDING",   (0,0), (-1,-1), 7),
        ("RIGHTPADDING",  (0,0), (-1,-1), 7),
        ("BOX",           (0,0), (-1,-1), 0.6, tc),
    ]))
    return tbl

ipsi_box   = feature_box("IPSILATERAL (same side as lesion) – below lesion", ipsi_items,   LRED,  RED)
contra_box = feature_box("CONTRALATERAL (opposite side) – below lesion",     contra_items, LBLUE, BLUE)

side_tbl = Table([[ipsi_box, Spacer(10, 1), contra_box]],
                  colWidths=[(CW-10)/2, 10, (CW-10)/2])
side_tbl.setStyle(TableStyle([
    ("VALIGN", (0,0), (-1,-1), "TOP"),
    ("TOPPADDING",    (0,0), (-1,-1), 0),
    ("BOTTOMPADDING", (0,0), (-1,-1), 0),
    ("LEFTPADDING",   (0,0), (-1,-1), 0),
    ("RIGHTPADDING",  (0,0), (-1,-1), 0),
]))
story.append(side_tbl)
story.append(Spacer(1, 5))

# At-level box
at_level_box = feature_box("AT THE LEVEL OF LESION (ipsilateral)", at_level_items,
                            LYELLOW, ORANGE)
story.append(at_level_box)
story.append(Spacer(1, 6))

# ── Causes ────────────────────────────────────────────────────────────────────
story.append(section_header("Causes / Aetiology"))
story.append(Spacer(1, 4))

cause_data = [
    [Paragraph("<b>Traumatic (most common)</b>", S("ch", fontSize=9.5, textColor=WHITE,
               fontName="Helvetica-Bold", leading=12)),
     Paragraph("<b>Non-traumatic</b>", S("ch", fontSize=9.5, textColor=WHITE,
               fontName="Helvetica-Bold", leading=12))],
    [Paragraph(
        "• Penetrating injury – stab wounds (most common overall)\n"
        "• Blunt trauma – hyperextension > flexion injuries\n"
        "• Herniated cervical disc (lateral)\n"
        "• Vertebral fracture-dislocation\n"
        "• Compression injuries",
        S("cb", fontSize=8.5, fontName="Helvetica", leading=14)),
     Paragraph(
        "• Multiple sclerosis (demyelinating plaques)\n"
        "• Spinal cord tumours – primary or metastatic\n"
        "• Spinal cord ischaemia / epidural haematoma\n"
        "• Hematomyelia\n"
        "• Posttraumatic / infectious arachnoiditis\n"
        "• Spinal subdural haematoma\n"
        "• Spinal cord herniation",
        S("cb", fontSize=8.5, fontName="Helvetica", leading=14))],
]
cause_tbl = Table(cause_data, colWidths=[CW/2, CW/2])
cause_tbl.setStyle(TableStyle([
    ("BACKGROUND",    (0,0), (-1,0), NAVY),
    ("BACKGROUND",    (0,1), (0,1), LGREY),
    ("BACKGROUND",    (1,1), (1,1), colors.HexColor("#eafaf1")),
    ("GRID",          (0,0), (-1,-1), 0.4, colors.HexColor("#aaaaaa")),
    ("VALIGN",        (0,0), (-1,-1), "TOP"),
    ("TOPPADDING",    (0,0), (-1,-1), 6),
    ("BOTTOMPADDING", (0,0), (-1,-1), 6),
    ("LEFTPADDING",   (0,0), (-1,-1), 8),
]))
story.append(cause_tbl)
story.append(Spacer(1, 6))

# ── BSS Plus ──────────────────────────────────────────────────────────────────
story.append(section_header("Brown-Séquard Plus Syndrome", bg=colors.HexColor("#6c3483")))
story.append(Spacer(1, 4))
story.append(Paragraph(
    "The <b>pure classic</b> form is rarely encountered clinically. More commonly, "
    "patients present with <b>Brown-Séquard Plus</b> (Taylor &amp; Gleave, 1957):",
    body))
story.append(bull("Asymmetrical hemiplegia rather than complete unilateral paralysis"))
story.append(bull("Hypoalgesia more prominent on the <i>less</i> paretic side"))
story.append(bull("Mixed/incomplete pattern of deficits"))
story.append(Paragraph(
    "<b>Prognosis note:</b> Paradoxically, pure BSS carries a <i>worse prognosis</i> than "
    "BSS Plus. Overall, BSS has the <b>best functional motor recovery</b> of all incomplete "
    "spinal cord syndromes. Most patients regain ambulatory function and bowel/bladder "
    "continence.",
    body))
story.append(Spacer(1, 6))

# ── Comparison table ──────────────────────────────────────────────────────────
story.append(section_header("Comparison with Other Incomplete Cord Syndromes"))
story.append(Spacer(1, 4))

comp_data = [
    [Paragraph("<b>Feature</b>", S("t", fontSize=9, textColor=WHITE, fontName="Helvetica-Bold")),
     Paragraph("<b>Brown-Séquard</b>", S("t", fontSize=9, textColor=WHITE, fontName="Helvetica-Bold")),
     Paragraph("<b>Central Cord</b>", S("t", fontSize=9, textColor=WHITE, fontName="Helvetica-Bold")),
     Paragraph("<b>Anterior Cord</b>", S("t", fontSize=9, textColor=WHITE, fontName="Helvetica-Bold")),
     Paragraph("<b>Posterior Cord</b>", S("t", fontSize=9, textColor=WHITE, fontName="Helvetica-Bold"))],
    ["Motor loss",
     "Ipsilateral UMN",
     "Arms > legs bilaterally",
     "Bilateral UMN (below)",
     "Mild or none"],
    ["Pain/Temp",
     "Contralateral loss",
     "Bilateral suspended 'cape'",
     "Bilateral loss below",
     "Preserved"],
    ["Proprioception/Vibration",
     "Ipsilateral loss",
     "Preserved",
     "Preserved",
     "Bilateral loss"],
    ["Common cause",
     "Penetrating trauma, MS",
     "Hyperextension (elderly)",
     "Anterior spinal artery infarct",
     "Posterior cord ischaemia"],
    ["Prognosis",
     "Best of all incomplete",
     "Good – arms worse than legs",
     "Variable",
     "Good"],
]
cw2 = [CW*0.16, CW*0.20, CW*0.20, CW*0.22, CW*0.22]
comp_tbl = Table(comp_data, colWidths=cw2)
comp_tbl.setStyle(TableStyle([
    ("BACKGROUND",    (0,0), (-1,0), TEAL),
    ("ROWBACKGROUNDS",(0,1), (-1,-1), [WHITE, LGREY]),
    ("GRID",          (0,0), (-1,-1), 0.4, colors.HexColor("#bbbbbb")),
    ("FONTNAME",      (0,0), (-1,0), "Helvetica-Bold"),
    ("FONTSIZE",      (0,0), (-1,-1), 8.5),
    ("VALIGN",        (0,0), (-1,-1), "TOP"),
    ("TOPPADDING",    (0,0), (-1,-1), 5),
    ("BOTTOMPADDING", (0,0), (-1,-1), 5),
    ("LEFTPADDING",   (0,0), (-1,-1), 5),
    ("FONTNAME",      (0,1), (0,-1), "Helvetica-Bold"),
]))
story.append(comp_tbl)
story.append(Spacer(1, 8))

# ── Memory Aid ────────────────────────────────────────────────────────────────
story.append(section_header("Memory Aid", bg=colors.HexColor("#1a6b3a")))
story.append(Spacer(1, 4))
mem_data = [[
    Paragraph(
        "<b>\"Same side – Motor and Posterior column loss\"</b><br/>"
        "Motor weakness + proprioception/vibration → <b>IPSILATERAL</b>",
        S("m", fontSize=9.5, textColor=BLACK, fontName="Helvetica", leading=14)),
    Paragraph(
        "<b>\"Opposite side – Pain and Temperature\"</b><br/>"
        "Pain and temperature loss → <b>CONTRALATERAL</b> (1–2 levels below)",
        S("m", fontSize=9.5, textColor=BLACK, fontName="Helvetica", leading=14)),
]]
mem_tbl = Table(mem_data, colWidths=[CW/2, CW/2])
mem_tbl.setStyle(TableStyle([
    ("BACKGROUND",    (0,0), (0,0), colors.HexColor("#d5f5e3")),
    ("BACKGROUND",    (1,0), (1,0), colors.HexColor("#d6eaf8")),
    ("BOX",           (0,0), (-1,-1), 0.6, colors.HexColor("#1a6b3a")),
    ("GRID",          (0,0), (-1,-1), 0.4, colors.HexColor("#aaaaaa")),
    ("TOPPADDING",    (0,0), (-1,-1), 8),
    ("BOTTOMPADDING", (0,0), (-1,-1), 8),
    ("LEFTPADDING",   (0,0), (-1,-1), 10),
]))
story.append(mem_tbl)
story.append(Spacer(1, 8))

# ── Footer ────────────────────────────────────────────────────────────────────
story.append(HRFlowable(width=CW, thickness=0.5, color=colors.HexColor("#aaaaaa")))
story.append(Spacer(1, 3))
story.append(Paragraph(
    "Sources: Adams &amp; Victor's Principles of Neurology 12e · Bradley and Daroff's Neurology in Clinical Practice · "
    "Neuroanatomy through Clinical Cases 3e · Guyton &amp; Hall Medical Physiology · "
    "Localization in Clinical Neurology 8e · Tintinalli's Emergency Medicine  |  "
    "Generated by Orris Medical AI · August 2026",
    S("foot", fontSize=7, textColor=colors.HexColor("#888888"), fontName="Helvetica-Oblique",
      alignment=TA_CENTER, leading=10)))

# ── Build ─────────────────────────────────────────────────────────────────────
doc.build(story)
print("PDF created successfully at", OUTPUT)
Running Command

python3 /tmp/workspace/bss-pdf/generate_bss_pdf.py

Running Command

ls -lh /tmp/workspace/bss-pdf/Brown_Sequard_Syndrome.pdf

Your PDF is ready (967 KB, single A4 page):

Brown Sequard Syndrome

PDF Document · PDF

The document includes:
  • Title block with full heading
  • Diagram (the one generated earlier showing ipsilateral vs. contralateral deficits)
  • Anatomical basis table - all three tracts, where they cross, and what deficit each produces
  • Clinical features - colour-coded boxes: red for ipsilateral deficits, blue for contralateral, yellow for at-level findings
  • Causes - traumatic vs. non-traumatic, side by side
  • Brown-Séquard Plus explanation with prognosis
  • Comparison table vs. Central Cord, Anterior Cord, and Posterior Cord syndromes
  • Memory aid - a quick two-box reminder for the exam
  • Source citations at the footer
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