Is LP Safe in Suspected IIH with Grade 5 Papilledema Before MR Venogram?

Short Answer: Yes, LP is generally safe - but MRI brain must already be normal, and the specific sequence matters.

The Key Principle: Why LP is Relatively Safe in IIH

"Neuroimaging, ideally brain MRI with contrast, is mandatory before lumbar puncture to rule out an intracranial mass as the cause for symptoms and signs."

• Bradley and Daroff's Neurology in Clinical Practice, p. 2459

Does MRV Need to Come First?

"Cerebral venography (MRV) should also be pursued, if possible, to rule out cerebral venous sinus thrombosis (an IIH mimic)... Neuroimaging, ideally MRI with contrast, is mandatory before LP."

If there is any suspicion of cerebral venous sinus thrombosis (CVST), LP carries a different risk profile. In CVST, therapeutic anticoagulation is the treatment - and if LP is done first, it complicates subsequent anticoagulation.

Grade 5 Papilledema - Does Severity Change Things?

1. Herniation risk is still low in pure IIH even with grade 5, as long as MRI shows no obstructive pathology. The pathophysiology does not create a pressure cone differential.
2. Grade 5 is actually an argument FOR doing LP sooner, not delaying it - it indicates markedly elevated ICP with risk of permanent visual loss. Therapeutic CSF drainage at LP can provide immediate ICP relief and protect the optic nerves.
3. The Alder Hey IIH Clinical Guideline (2024) specifically calls for LP after MRI brain (not necessarily after MRV), and states that if opening pressure is elevated, CSF should be drained to reduce ICP by ~30%.
4. The JNNP consensus guidelines (Mollan et al., 2018) state:

"Following normal imaging, all patients with papilloedema should have a lumbar puncture to check opening pressure and ensure contents are normal."

Practical Recommendation for Your Patient

When Would You Delay LP for MRV?

• Clinical features suggest CVST (thunderclap onset, seizure, focal deficits, male patient, postpartum, hypercoagulable state)
• MRI shows findings suspicious for venous thrombosis (parenchymal hemorrhage in atypical location, hyperdense sinus)
• Your patient has red flag features that make CVST the more likely diagnosis

Bottom Line

Methylene Blue in Methemoglobinemia - Dosing

Standard Dose

• Harrison's 22E confirms: "The usual dose is 1-2 mg/kg IV"
• Tintinalli's Emergency Medicine confirms: "Initial dose is 1 mg/kg (0.1 mL/kg of 1% solution)"

When to Give It

Repeat Dosing

• If no significant improvement within 30-60 minutes, repeat at 1 mg/kg
• For unstable/arrest patients (MetHb >50%): may repeat at 15-60 min

Maximum Dose

7 mg/kg total over 24 hours

• Above 7 mg/kg, methylene blue paradoxically causes methemoglobinemia (it acts as an oxidant at high doses)

Mechanism (Quick Summary)

Critical Contraindication: G6PD Deficiency

• Methylene blue requires NADPH (which depends on G6PD activity)
• In G6PD deficiency: methylene blue is ineffective AND causes hemolytic anemia - do NOT use
• Alternative: IV ascorbic acid (vitamin C), exchange transfusion, or hyperbaric oxygen

Practical Notes

• Follow each dose with 15-30 mL NS flush
• Co-administration of dextrose (1 mEq/kg) helps replenish NADPH cofactors
• Pulse oximetry will show a spurious drop in SpO₂ for 10-30 min after dosing - this is a dye artifact, not true desaturation
• Methylene blue has MAOI activity - avoid with serotonergic drugs (serotonin syndrome risk)
• Urine and skin may turn blue-green - reassure the patient

If Methylene Blue Fails

How to Write Squint (Strabismus) in a Clinical Case

Step 1 - Inspection (Write what you see)

"On inspection, there is a convergent squint (esotropia) of the right eye / divergent squint (exotropia) of the right eye."

Step 2 - Specify Paralytic vs Concomitant

• Concomitant (non-paralytic): Angle of squint remains the same in all directions of gaze. Usually childhood onset, no diplopia.
• Paralytic (incomitant): Angle of squint changes with direction of gaze. Diplopia present. Ask which muscle/nerve is affected.

"The squint is concomitant / paralytic in nature."

Step 3 - Identify the Nerve/Muscle Involved (in Paralytic Squint)

• S Das Clinical Surgery, p. 5809-5817

Step 4 - Cover Test (Mention in Examination)

"On cover-uncover test, the uncovered eye makes a corrective movement to fix the target, confirming the presence of squint."

• Movement inward on uncovering = exotropia
• Movement outward on uncovering = esotropia

Step 5 - Corneal Light Reflex (Hirschberg Test)

"Hirschberg corneal light reflex test shows asymmetric light reflex - the reflex is displaced nasally in the right eye, consistent with exotropia."

How to Write Pupil Examination in a Clinical Case

S - Size

"Both pupils are equal in size, measuring approximately 3 mm in diameter" OR "Right pupil is dilated (6 mm), left pupil is 3 mm"

S - Shape

"Both pupils are round and regular in shape" OR "Right pupil is irregular in shape"

A - Light Reaction (Direct and Consensual)

"Direct and consensual light reflexes are present and equal bilaterally"

R - Accommodation Reflex

"Accommodation reflex is intact bilaterally" OR "Pupil constricts on near vision but not to light - Light-Near Dissociation (Argyll Robertson pupil)"

Full Model Write-Up for Examination

EYES:
- On inspection: Convergent squint of the right eye noted.
- Hirschberg corneal reflex test: asymmetric, reflex displaced 
  temporally in right eye.
- Cover test: Right eye makes inward corrective movement on 
  uncovering - consistent with right esotropia.
- Ocular movements: Full range of movement in all directions / 
  Limitation of abduction of right eye noted.
- Diplopia: Present / Absent.
- Nature of squint: Paralytic / Concomitant.

PUPILS:
- Size: Right 3 mm, Left 3 mm - equal bilaterally.
- Shape: Round and regular.
- Direct light reflex: Present bilaterally.
- Consensual light reflex: Present bilaterally.
- RAPD: Absent / Present on right side (Marcus Gunn pupil).
- Accommodation reflex: Intact bilaterally.

Quick Tip for Viva

• CN III: Ptosis + Externoinferior squint + Dilated pupil (surgical CN III) or normal pupil (medical CN III - diabetes/HTN)
• CN VI: Pure convergent squint, no ptosis, no pupil change
• CN IV: Head tilt to opposite side (to compensate), hypertropia worse on downgaze

Bilateral 6th Nerve (Abducens) Palsy

Clinical Features

• Bilateral convergent squint (both eyes turned inward due to medial rectus unopposed)
• Bilateral failure of abduction (cannot move either eye outward)
• Bilateral horizontal diplopia, worse on lateral gaze
• Patient may adopt a face-turn to compensate
• No ptosis, no pupil change (CN VI has no pupillary fibers)

Why Bilateral? - The Key Anatomical Reason

Causes of Bilateral 6th Nerve Palsy

A - Raised Intracranial Pressure (Most Important Cause)

• Adams & Victor's Neurology: "Isolated unilateral or bilateral sixth nerve palsy with global headache can be the initial manifestation of raised intracranial pressure from any source - including brain tumor, meningitis, and pseudotumor cerebri"

B - Brainstem (Pontine) Lesions

C - Meningeal/Basal Pathology (Bilateral Diffuse)

D - Petrous Apex

• Gradenigo syndrome: Unilateral usually, but bilateral if symmetric - CN VI palsy + retroorbital pain (CN V1) + deafness (CN VIII)
• Caused by: petrous apex osteomyelitis, cholesteatoma, trauma

E - Cavernous Sinus

• Bilateral cavernous sinus thrombosis (rare)
• Bilateral cavernous sinus meningioma
• Pituitary apoplexy

F - Metabolic / Systemic

Investigation Approach

Bilateral CN VI palsy
        ↓
1. MRI Brain (with contrast) - URGENT
   - Exclude mass, pontine lesion, hydrocephalus
2. MRI/MRA of posterior fossa and clivus
3. Fundus exam - papilledema? → raised ICP
4. LP (after MRI clears mass):
   - Opening pressure
   - CSF cells, protein, glucose
   - Gram stain, culture, AFB, India ink
   - Cytology if malignancy suspected
5. Bloods: thiamine, B12, glucose, TFTs
6. Chest X-ray/CT (sarcoid, TB, malignancy)

High-Yield Associations for Exams

History & Clinical Examination for Inflammatory Myopathy (Polymyositis / Dermatomyositis / IBM)

HISTORY TAKING

1. Chief Complaint - Characterize the Weakness

• Which muscles are weak? (Upper limb, lower limb, neck?)
• Proximal or distal? - Proximal = myopathy; distal = neuropathy
• Is it symmetric or asymmetric?
• Onset: Sudden / subacute (weeks-months) / chronic (years)?
• Progression: Worsening / static / fluctuating?

"Muscle weakness is subacute in onset, symmetric, and typically affects the proximal muscles first" - Robbins Pathology

2. Functional Disability Questions (Proximal Muscle Weakness Screening)

3. Muscle Symptoms

• Myalgia - pain in muscles at rest or on movement? (More in PM/DM than IBM)
• Muscle tenderness - touch-triggered pain?
• Muscle cramps?
• Muscle stiffness - morning stiffness? (differentiates from PMR)
• Muscle swelling or wasting - noticed any wasting?
• Fatigue - disproportionate fatigue with exertion?

4. Extra-Muscular Symptoms (Very Important in DM/PM)

Skin (Dermatomyositis-specific - ask all)

• Rash on eyelids - violet/purple discoloration? (heliotrope rash)
• Rash on knuckles - scaly red patches over knuckles/elbows/knees? (Gottron papules)
• Facial rash - V-sign on chest, shawl sign on back?
• Nail fold changes - dilated capillaries, ragged cuticles?
• Skin thickening on hands - "mechanic's hands" (anti-synthetase syndrome)
• Calcinosis - calcium lumps under skin? (esp. juvenile DM)
• Photosensitivity?

Respiratory

• Breathlessness on exertion? - ILD occurs in up to 45% with anti-synthetase antibodies
• Dry cough?
• Respiratory muscle weakness - orthopnea?

Swallowing / Voice

• Dysphagia - difficulty swallowing solids/liquids? (oropharyngeal/esophageal involvement - 1/3 of DM patients)
• Nasal regurgitation?
• Hoarse voice / nasal speech?
• Aspiration / choking?

Joints

• Arthralgia / arthritis - swollen painful joints? (part of anti-synthetase syndrome)
• Morning stiffness duration?
• Raynaud's phenomenon - color change of fingers in cold? (anti-synthetase syndrome)

Cardiac

• Palpitations / chest pain? - myocarditis, arrhythmias (esp. anti-SRP IMNM)
• Ankle swelling? - cardiac failure from cardiomyopathy

5. Positive History Points Strongly Suggesting Inflammatory Myopathy

• Subacute onset proximal symmetric weakness
• Heliotrope rash / Gottron papules (DM)
• Dysphagia with muscle weakness
• Breathlessness + muscle weakness (ILD + myositis)
• Female, middle age (PM/DM peak: 40-60 yrs)
• Raynaud's + arthritis + mechanic's hands + ILD = anti-synthetase syndrome
• Older male (>50 yrs) with slowly progressive quadriceps + distal hand weakness = IBM

6. Drug History (Critical - Rule Out Drug-Induced Myopathy)

7. Past Medical History

• Connective tissue disease - SLE, RA, Sjogren's, scleroderma, mixed CTD? (overlap myositis)
• Malignancy - any known cancer? (DM is strongly associated with malignancy, esp. anti-TIF1-γ over age 38)
• Thyroid disease - hypo/hyperthyroidism both cause myopathy
• Diabetes - metabolic myopathy
• Renal disease - electrolyte disturbances (hypokalemia, hypophosphatemia → myopathy)

8. Family History

• Any family member with muscular dystrophy, myopathy, or neuromuscular disease?
• (Helps differentiate hereditary myopathies from inflammatory)

9. Social History

• Occupation - any toxic exposures?
• Alcohol use - quantity, duration?
• Smoking - risk for malignancy-associated DM
• Diet - vitamin D / nutrition status?

10. Negative History to Specifically Ask and Document

CLINICAL EXAMINATION

General Examination

• Build: Obese? (steroid myopathy) / Cachexia? (malignancy)
• Skin color: Rash distribution
• Nails: Dilated nailfold capillaries, ragged cuticles
• Lymphadenopathy (malignancy screen)
• Fever? (acute inflammatory phase)

Skin Examination (DM Specific)

Musculoskeletal Examination

• Wasting - proximal > distal (myopathy pattern)
• Fasciculations absent (absent = against MND)
• Pseudohypertrophy absent (against DMD)

• Palpate deltoids, biceps, quadriceps, gastrocnemii
• Tenderness present in inflammatory myopathy (absent in dystrophies)

• Deep tendon reflexes: Usually preserved in early myopathy
• Lost in late/severe disease
• Absent early = think neuropathy or IBM

• Normal in pure myopathy
• Document: "Sensation intact to all modalities" - this is an important negative

Other System Examination

Summary Pattern Recognition

• Robbins Pathology, p. 1134-1135
• Harrison's Principles of Internal Medicine 22E

CLINICAL CASE ANALYSIS

Patient Identification

SYMPTOM ANALYSIS

Presenting Complaint

Detailed Characterisation of the Current Episode (20/5/26 onwards)

Functional Impact (Proximal Muscle Weakness Pattern)

• Cannot get up from chair / squatting position
• Cannot climb stairs
• Difficulty walking independently (requires support)
• Difficulty getting out of bed

LOCALIZATION

Level of Lesion: Muscle (Myopathy) OR Motor Nerve (Axonal Neuropathy)

NCS/EMG Results (from investigations):

• NCS: Pure motor axonal neuropathy (CPK 380)
• EMG: MUAP in RT TA / RT Vastus lateralis / RT Biceps - early recruitment → suggests MYOPATHIC pattern (small amplitude, early recruitment)
• Myositis panel: NEGATIVE
• Repeat CPK: 19 (near normal - important!)
• MRI muscle: Subcutaneous edema in both legs (not intramuscular signal change)

Localization Conclusion:

POINTS IN FAVOUR (of each diagnosis)

1. STEROID MYOPATHY (Most Likely)

• Started Wysolone 40 mg OD exactly 4-5 days before weakness onset - tight temporal correlation
• Proximal, symmetric, painless weakness - classic steroid myopathy phenotype
• Normal / near-normal CK (repeat CPK = 19) - hallmark of steroid myopathy (CK is normal because no muscle necrosis, just protein synthesis inhibition in Type II fibers)
• No muscle tenderness, no stiffness - against inflammatory myopathy
• Myositis panel negative - against PM/DM
• EMG showing early recruitment = myopathic pattern
• Type II fiber atrophy on biopsy would confirm (if done)

"Symmetrical, painless myopathy without neurological signs, normal CK levels, and EMG would favor corticosteroid-induced myopathy" - Rheumatology, Elsevier 2022

• 40 mg/day dose is moderate - steroid myopathy more common with higher/longer doses
• Only 4-5 days of steroid - usually takes weeks (though can occur early)
• NCS shows axonal neuropathy (not explained by steroids alone)

2. INFLAMMATORY MYOPATHY (PM/DM/IMNM)

• CPK first value = 380 (mildly elevated)
• Subacute onset proximal weakness
• Could be triggered by immune dysregulation from underlying IBD/LCH

• Myositis panel NEGATIVE - strongest point against
• No skin rash - against dermatomyositis
• No muscle tenderness - against PM
• Repeat CPK = 19 - extremely low, against active myositis (would expect >1000 in PM/DM)
• No fatigability, no diurnal variation - against
• MRI muscle shows only subcutaneous edema, not myositis signal

3. CIDP / GBS RECURRENCE / MOTOR AXONAL NEUROPATHY

• Strong past history of GBS in 2022 (post-Covishield vaccine)
• NCS shows pure motor axonal neuropathy - consistent with AMAN variant
• IVIG given (2g/kg) at IGMS Patna - correct treatment for GBS/CIDP
• No improvement with IVIG - but AMAN can have delayed recovery

• EMG shows myopathic pattern (early recruitment) - not denervation pattern
• No sensory symptoms in GBS usually there are some
• CSF normal (CSF n) - no albumino-cytological dissociation (expected in GBS/CIDP)
• Proximal distribution without distal involvement - GBS usually ascending from distal
• No areflexia documented (GBS hallmark)
• Previous GBS episode fully resolved with no residual weakness

4. AZATHIOPRINE-INDUCED NEUROPATHY/MYOPATHY

• Started simultaneously with steroids
• Azathioprine is known to cause:
  • Hepatotoxicity (patient already has CLD)
  • Rarely peripheral neuropathy
  • Drug fever

• Azathioprine myopathy/neuropathy is rare and usually develops over weeks-months
• Onset too rapid (4-5 days) for azathioprine toxicity

5. HYPOKALEMIC MYOPATHY (from Wysolone + Dytor)

• Patient is on Wysolone (causes renal K+ wasting) + Dytor (Torsemide - loop diuretic) - both independently cause hypokalemia
• Combination = high risk for severe hypokalemia
• Hypokalemic myopathy: proximal weakness, can be severe
• Worsened by diarrhea (further K+ loss)
• CLD + diarrhea + diuretic + steroid = perfect storm for hypokalemia

• No mention of serum electrolytes in records provided
• No muscle cramps documented
• No mention of cardiac arrhythmia

⚠️ This is a critical and potentially reversible cause that must be excluded first!

6. CLD-RELATED MYOPATHY (Sarcopenic/Hepatic Myopathy)

• Decompensated CLD confirmed (pedal edema, ascites/abdominal distension, facial puffiness)
• 25 kg weight loss since February - severe malnutrition/sarcopenia
• Hepatic myopathy: proximal weakness from vitamin D deficiency, zinc deficiency, protein-calorie malnutrition
• Hyperammonemia can cause encephalopathy + weakness

• Weakness onset acute (4-5 days after drugs) rather than gradual with CLD progression
• CLD was present since February but weakness only from May - does not fully explain timing

ASSOCIATIONS BETWEEN DISEASES IN THIS PATIENT

1. LCH → Immunological Dysregulation → GBS → Crohn's Disease

LCH (2002)
    ↓ Immune dysregulation / abnormal histiocyte activation
GBS (2022, post-vaccine trigger)
    ↓ Aberrant immune response
Crohn's Disease (2026)
    ↓ IBD-associated neuropathy/myopathy
Current Weakness

• LCH is a clonal disorder of myeloid dendritic cells - associated with immune dysregulation
• GBS post-vaccine suggests predisposition to aberrant immune responses
• Crohn's disease extraintestinal manifestations include peripheral neuropathy (in 5-10%), inflammatory myopathy, and reactive arthropathy

2. Crohn's Disease + Peripheral Neuropathy

• IBD-associated neuropathy is well recognized
• Can be: axonal, demyelinating, mononeuritis multiplex, or myopathic
• Mechanism: immune-mediated, nutritional (B12, folate, B1), drug-induced

3. CLD in Crohn's Disease

• Primary sclerosing cholangitis (PSC) is strongly associated with IBD (esp. UC, but also Crohn's)
• Autoimmune hepatitis can co-exist with IBD
• Could the liver disease be IBD-associated rather than isolated?

4. Family History

• 2nd brother and 5th brother both deceased (cause unknown)
• Father and mother alive
• Raises question of familial immunodeficiency / storage disorder / metabolic disease
• LCH + Crohn's in the same person is unusual - may suggest underlying immune dysregulation
• Need to know cause of brothers' deaths - if similar systemic disease → consider hereditary condition

DIFFERENTIAL DIAGNOSIS (Ranked by Probability)

CRITICAL NEXT STEPS

1. Serum electrolytes (K+, Mg2+, Phosphate) - rule out hypokalemia URGENTLY
2. Repeat CK (trend) - if <100 = steroid myopathy likely
3. Steroid dose reduction trial - if weakness improves = confirms steroid myopathy
4. CSF analysis (done - reported normal, argues against GBS/CIDP)
5. Nerve biopsy if NCS/EMG discordance persists
6. Muscle biopsy (gold standard) - would show Type II fiber atrophy in steroid myopathy vs necrosis in IMNM
7. Vitamin D, B12, Folate, Zinc levels (nutritional myopathy in CLD)
8. Liver workup - PSC/AIH in context of IBD
9. LCH restaging - has it recurred? CNS/bone involvement?
10. Cause of death of 2nd and 5th brothers - genetic workup if relevant

SUMMARY STATEMENT

38-year-old male with LCH (2002), GBS (2022), decompensated CLD (2026), and Crohn's disease (2026) presenting with acute-onset bilateral lower limb proximal weakness 4-5 days after starting Wysolone 40mg + Azathioprine + Torsemide, with near-normal CK, negative myositis panel, normal CSF, NCS showing pure motor axonal neuropathy, and EMG showing myopathic changes. The most likely diagnosis is steroid-induced myopathy with possible contributory hypokalemia (steroids + diuretic + diarrhea), superimposed on an underlying axonal motor neuropathy from Crohn's disease. IVIG non-response argues against GBS recurrence. Hypokalemia must be excluded urgently as a reversible cause.

PRIMARY IMMUNE REGULATORY DISORDERS (PIRDs) - Case Correlation

This patient has LCH (2002) + GBS (2022) + Crohn's-like enteropathy (2026) + autoimmune liver disease/CLD (2026) + neuromuscular weakness - a constellation that is strongly suggestive of an underlying monogenic immune dysregulatory disorder rather than multiple coincidental diseases.

CONCEPT: Why Think PIRDs Here?

• CTLA-4 to downregulate T cell activation
• LRBA to recycle CTLA-4 back to the cell surface (LRBA deficiency effectively = functional CTLA-4 deficiency)
• STAT3 in balanced signaling to prevent excessive T cell activation

Childhood/young adult: LCH (abnormal histiocyte/DC activation - immune dysregulation)
         ↓
2022: Post-vaccine GBS (exaggerated immune response to vaccine antigen)
         ↓
2026: Crohn-like enteropathy + CLD (lymphocytic gut + liver infiltration)
         ↓
2026: Neuromuscular weakness (lymphocytic muscle/nerve infiltration?)

1. CTLA-4 HAPLOINSUFFICIENCY (CHAI Disease)

Mechanism

• Inheritance: Autosomal dominant (heterozygous mutation)
• Penetrance: 60-70% (carrier family members may be asymptomatic!)

Relevance to This Case

Neurological Manifestations in CTLA-4-H

• Autoimmune encephalitis
• Perivascular lymphocytic infiltration
• Inflammatory neuropathy (GBS-like)
• Demyelinating disease

"Neurological involvement may be underestimated in CTLA4 deficiency because of predominant extra-neurologic features... neurologic manifestations should be taken into consideration in the diagnostic work-up" - MDPI Genes 2025

Against

• Typically pediatric/young adult onset (but can present in adults with delayed penetrance)
• No documented family history of similar illness (but brothers died - cause unknown)
• Autosomal dominant - need to check parents and surviving siblings
• Need genetic testing to confirm

2. LRBA DEFICIENCY

Mechanism

• Inheritance: Autosomal recessive (biallelic mutations)
• Prevalence: Higher in consanguineous populations (common in Bihar/North India)
• Phenotypically overlaps with CTLA-4-H but generally more severe and earlier onset

Relevance to This Case

Key Differentiator from CTLA-4-H

• LRBA = autosomal recessive - need to check if parents are consanguineous or carriers
• LRBA deficiency is prevalent in South Asia and Middle East due to consanguinity
• The 2 deceased brothers (2nd and 5th) - if they died from similar multi-system disease in childhood/young adulthood → strongly suggests AR inheritance
• LRBA cases often initially misdiagnosed as CVID (common variable immunodeficiency)

Treatment Implication

3. STAT3 GAIN-OF-FUNCTION (GOF) SYNDROME

Mechanism

• Inheritance: Autosomal dominant (de novo or familial)
• Onset: Typically early childhood (median 2.3 years) - but can present atypically

Relevance to This Case

"Clinical manifestations encompass enteropathy, skin disease, pulmonary disease, endocrinopathy, arthritis, autoimmune hepatitis, and rarely neurologic disease and myopathy" - PMC9948021

Against

• Onset typically in early childhood - this patient is 38 with late presentation
• However: STAT3 GOF can have highly variable age of onset and severity
• LCH (2002) at ~14 years could represent the first manifestation
• Malignancy risk (lymphoma) - brothers' deaths from unknown cause?

COMPARATIVE TABLE: Patient vs All Three PIRDs

PRIORITY RANKING FOR THIS PATIENT

1st - LRBA Deficiency (Strongest Candidate)

• Bihar origin (consanguinity possible)
• Two brothers deceased - autosomal recessive pattern fits perfectly
• Enteropathy + liver disease + lymphadenopathy + recurrent infection (TB) + neuropathy
• Started with childhood/adolescent manifestation (LCH 2002 at ~14 yrs)
• Hypogammaglobulinemia + poor vaccine response could explain GBS post-vaccine

2nd - CTLA-4 Haploinsufficiency

• Multi-organ autoimmunity + lymphadenopathy + neurological involvement
• Adult onset with variable penetrance
• Autosomal dominant - check surviving family members
• GBS-like neuroinflammation is documented in CTLA-4-H

3rd - STAT3 GOF

• All features present including rare myopathy
• Fits clinically but age of onset is atypical
• Two deceased brothers could have died from early-onset severe disease

WHAT TO DO NEXT - PIRD WORKUP

Immediate Blood Tests

1. Serum immunoglobulins - IgG, IgA, IgM
   (low IgG + IgA = CVID-like = LRBA/CTLA-4-H)
2. Lymphocyte subset panel (flow cytometry):
   - Total CD4, CD8, CD19 (B cells), NK cells
   - CD4+CD25+FoxP3+ Tregs (LOW in CTLA-4-H and LRBA)
3. Vaccine antibody titres (anti-tetanus, anti-pneumococcal)
   (poor response = immune deficiency)
4. CTLA-4 surface expression on T cells (flow cytometry)
   (reduced in CTLA-4-H and LRBA)
5. ANA, anti-dsDNA, ANCA, anti-LKM (autoimmune screen)

Genetic Testing

Priority panel:
- CTLA4 gene sequencing (heterozygous mutation)
- LRBA gene sequencing (biallelic mutations)
- STAT3 gene sequencing (GOF mutations - specific exons)
- Whole exome sequencing (WES) if above negative

Family Studies

• Test surviving brothers (1st and 6th) and parents for CTLA4/LRBA mutations
• Determine cause of death of 2nd and 5th brothers - critical information
• If brothers died from lymphoma / multi-organ failure / immunodeficiency → strongly supports AR LRBA deficiency

Treatment Implication

Abatacept (CTLA-4-Ig) is the disease-specific therapy - replaces missing CTLA-4 function, dramatically improves enteropathy, liver disease, and neurological manifestations

Ruxolitinib (JAK1/2 inhibitor) or Baricitinib - block excessive STAT3 signaling

Summary Statement

This 38-year-old male with LCH (2002), GBS (2022), Crohn's-like enteropathy + autoimmune CLD (2026), and neuromuscular weakness represents a unified monogenic immune dysregulatory syndrome rather than multiple separate diagnoses. The constellation most closely fits LRBA deficiency (autosomal recessive - supported by 2 deceased brothers and geographic background) or CTLA-4 haploinsufficiency (supported by adult-onset, documented neurological involvement, variable penetrance). STAT3 GOF is a third possibility. A PIRD genetic panel (CTLA4 + LRBA + STAT3 sequencing + WES) is the single most important next investigation. This diagnosis, if confirmed, completely changes the therapeutic approach - from steroids/azathioprine (which may be harmful) to abatacept (disease-specific targeted therapy).

IIH (Idiopathic Intracranial Hypertension) - Complete Treatment Protocol

GOALS OF TREATMENT

1. Protect vision (prevent permanent visual loss - the most critical goal)
2. Reduce ICP (relieve papilledema and headache)
3. Treat underlying cause (especially obesity/weight)
4. Reduce headache morbidity

STEP 1 - INITIAL ASSESSMENT (Before Starting Treatment)

• Fundus exam + Frisen grading of papilledema (Grade 0-5)
• Visual field testing (automated Humphrey perimetry) - baseline and monitoring
• Visual acuity (Snellen chart)
• OCT of optic nerve (retinal nerve fiber layer thickness) - best objective monitor
• LP opening pressure (confirmed diagnosis + therapeutic)
• MRI brain + MRV (exclude CVST, mass lesion)
• BMI calculation - virtually always relevant

STEP 2 - LIFESTYLE MODIFICATION (All Patients - Non-Negotiable)

Weight Loss

• 10% weight loss → ~40% reduction in ICP (Wall et al.)
• Target: minimum 10% body weight reduction
• In IIHTT trial: weight loss of 15.7 kg on average → reduced ICP, improved papilledema
• Dietary counselling + caloric restriction: 400-500 kcal/day deficit
• Low-sodium diet: reduces fluid retention

"Weight reduction is always advised if the patient is overweight" - Adams & Victor's Neurology

Activity

• Regular aerobic exercise
• Avoid activities that chronically raise intrathoracic pressure (e.g. wind instruments)

STEP 3 - MEDICAL TREATMENT

1st Line: Acetazolamide (Carbonic Anhydrase Inhibitor)

• Paresthesias (hands, feet, perioral) - most common, often dose-limiting
• Nausea, dysgeusia (metallic taste in carbonated drinks)
• Kidney stones (long-term use) - hydration important
• Hypokalemia - monitor electrolytes
• Fatigue, cognitive slowing
• Teratogenic - Category D in pregnancy (avoid)
• Contraindicated in sulfa allergy

2nd Line: Topiramate

• Cognitive dulling / "topamax stupidity" - word-finding difficulty
• Weight loss (therapeutic in IIH)
• Kidney stones (like acetazolamide - both are CA inhibitors)
• Teratogenic - neural tube defects (contraindicated in pregnancy)
• Paresthesias

Acetazolamide + Topiramate combination lowers ICP more than either alone (2024 experimental evidence) - consider in refractory cases

Adjunctive: Furosemide / Loop Diuretics

• Furosemide 20-80 mg BD as add-on to acetazolamide
• Reduces CSF production + fluid retention
• Short-term impact only
• Monitor K+, renal function
• Useful in patients awaiting surgery or with acute exacerbations

Role of Corticosteroids

• Not recommended for long-term use in IIH
• Chronic steroid use actually worsens IIH (rebound ICP rise on tapering, weight gain)
• Short-term IV methylprednisolone (250 mg QID x 5 days + oral taper) may be used for acute severe visual loss only, as a bridge to surgery
• Causes rebound ICP increase on withdrawal

Emerging: GLP-1 Receptor Agonists (New - 2024-2025)

• Semaglutide, Liraglutide - strong evidence for weight loss → ICP reduction
• The 2025 systematic review (PMID 41057780) supports GLP-1 agonists as emerging adjunctive therapy for IIH
• Mechanism: weight loss + possible direct reduction in CSF production via GLP-1 receptors in choroid plexus
• Not yet in formal guidelines but increasingly used in clinical practice

STEP 4 - MONITORING RESPONSE

• Visual acuity
• Visual fields (Humphrey perimetry) - most important monitor
• Fundus exam (papilledema grade)
• OCT of optic nerve head
• Weight / BMI
• Headache frequency and severity
• Repeat LP opening pressure (if clinical deterioration)

• Visual acuity drop to < 20/20
• Enlarging blind spot
• Inferonasal sector field defects
• Grade 4-5 papilledema with progressive loss
• Fulminant IIH (rapid visual loss within weeks)

STEP 5 - SURGICAL TREATMENT (Refractory / Severe Disease)

Indications for Surgery

• Progressive visual field loss despite maximal medical therapy
• Severe vision loss at presentation (fulminant IIH)
• Drug intolerance preventing adequate medical treatment
• Headache refractory to all medical therapy

A. Optic Nerve Sheath Fenestration (ONSF)

• Fenestrations (multiple cuts) in the optic nerve sheath → CSF decompression directly around optic nerve
• Primarily protects optic nerve from compressive damage
• Does not reliably relieve headache
• Can be repeated
• Complications: visual field loss (10%), diplopia, pupil abnormalities, orbital swelling

B. CSF Diversion (Shunting)

• LP shunt: 70% improve headache; 70% improve vision (Adams & Victor)
• High revision rate in obese patients (shunt blockage, dislodgement, back/sciatic pain)
• VP shunt: better long-term patency, requires larger surgery
• Both: risk of overdrainage, low-pressure headache, infection, migration

C. Cerebral Venous Sinus Stenting

• For patients with significant transverse sinus stenosis (found on MRV in most IIH)
• Stenting stenotic sinus → reduces upstream venous hypertension → reduces ICP
• Emerging procedure; good results in selected patients
• Risk: stent thrombosis, venous perforation

D. Bariatric Surgery

• For morbidly obese patients (BMI > 40 or > 35 with comorbidities)
• 24-patient study: satisfactory ICP reduction and symptom improvement over several years
• Addresses the root cause in obese IIH
• Significant GI side effects from procedure itself

E. Urgent Temporizing Measures (Fulminant IIH)

• Serial lumbar punctures (drain CSF to normal pressure each time)
• Lumbar drain (continuous CSF drainage temporarily)
• IV acetazolamide + short-course IV steroids

COMPLETE TREATMENT ALGORITHM

IIH Confirmed (Papilledema + LP OP >25 cmH2O + Normal MRI)
                        ↓
         ┌──────────────────────────────┐
         │   ALL PATIENTS:              │
         │   • Weight loss (10%+)       │
         │   • Low sodium diet          │
         │   • Acetazolamide 250-500mg  │
         │     BD → titrate to 4g/day   │
         └──────────────────────────────┘
                        ↓
         Monitor every 4-6 weeks (VF, VA, OCT, fundus)
                        ↓
    ┌───────────────────────────────────────┐
    │          Intolerant to Acetazolamide? │
    └────────────────┬──────────────────────┘
                     ↓ Yes
             Switch to Topiramate
             100-200 mg/day
                        ↓
    ┌───────────────────────────────────────┐
    │       Partial response?               │
    └────────────────┬──────────────────────┘
                     ↓ Yes
        Add Furosemide 20-80mg BD
        Consider adding Topiramate to Acetazolamide
        GLP-1 agonist if obese
                        ↓
    ┌───────────────────────────────────────┐
    │   Progressive visual loss / Refractory│
    └────────────────┬──────────────────────┘
                     ↓
         ┌─────────────────────────┐
         │ Vision-threatening?     │
         │ → ONSF                  │
         │                         │
         │ Headache + visual sx?   │
         │ → LP or VP shunt        │
         │                         │
         │ Transverse sinus        │
         │ stenosis on MRV?        │
         │ → Venous sinus stenting │
         │                         │
         │ Morbidly obese?         │
         │ → Bariatric surgery     │
         └─────────────────────────┘

HEADACHE MANAGEMENT IN IIH (Often Overlooked)

• Avoid analgesic overuse (>15 days/month) - medication overuse headache is very common in IIH and makes headache worse
• Topiramate is preferred as both ICP-lowering AND headache prophylaxis agent
• Amitriptyline / Nortriptyline for headache prophylaxis (but may cause weight gain - use cautiously)
• Avoid NSAIDs long-term (may worsen renal prostaglandin-mediated CSF resorption)
• Treat migraine features specifically if present (triptans for acute attacks)

SPECIAL SITUATIONS

Key Evidence Base

• IIHTT Trial (2014) - [Wall et al., NEJM]: Acetazolamide + low-sodium weight-reduction diet improves visual fields and papilledema at 6 months vs. placebo (PMID 26587993 for safety data)
• Mollan et al. 2018 - JNNP Consensus Guidelines on Management (most widely cited guideline)
• GLP-1 agonists 2025 - Systematic review supports emerging role (PMID 41057780)
• Adams & Victor's Principles of Neurology, 12th Ed.
• Tintinalli's Emergency Medicine, 9th Ed.