Dr Bilal Ahmed -Neurophysician/Neurologist

16/06/2026

🔲 1. Normal / Idiopathic Parkinson Disease (Left Profile)
🧠 Condition: Normal probands & Idiopathic Parkinson disease

🦆 Mnemonic Shape: The Normal / Penguin Silhouette

Explanation: This profile shows a normal, healthy relationship between the midbrain (the head), the pons (the large bulging belly), and the medulla (the body). In classic Parkinson's disease, the overall sagittal silhouette of the brainstem remains preserved and looks normal.

🔲 2. Progressive Supranuclear Palsy (Middle Profile)
🧠 Condition: Progressive Supranuclear Palsy (PSP)

🕊️ Mnemonic Shape: The Hummingbird / King Penguin Sign

Explanation: The silhouette shows severe thinning (atrophy) of the midbrain at the top, while the pons below stays relatively plump. This gives it the characteristic appearance of a hummingbird with a long, thin beak or a king penguin looking upward.

🔲 3. Multiple System Atrophy (Right Profile)
🧠 Condition: Multiple System Atrophy (cerebellar type / MSA-C)

📉 Mnemonic Shape: The Shrunken Pons Silhouette

Explanation: Unlike the middle image, this silhouette displays significant flattening and shrinking (atrophy) of the central pons bulge. Because the pons loses its normal rounded "belly" shape, the brainstem profile becomes much straighter and narrowed.

12/05/2026

Now available in jhelum

25/04/2026

23/02/2026

Midbrain Syndromes

Weber syndrome
• Ipsilateral CN III palsy
• Contralateral hemiparesis
• Caused by PCA infarct (cerebral peduncle)

Benedikt syndrome
• Ipsilateral CN III palsy
• Contralateral ataxia, tremor
• Red nucleus involvement

Claude syndrome
• Combination of Weber + Benedikt
• CN III palsy + contralateral ataxia + weakness

Parinaud syndrome
• Upward gaze palsy
• Light–near dissociation
• Pineal tumor association

22/02/2026

Demyelinating Brain disease on Imagining..


.

19/02/2026

Nondisabling mild stroke

typically, NIHSS ≤ 5 with nondisabling deficit

such a deficit does not limit the independent activities of daily living (ADLS) or return to work (AHA/ASA 2026)

isolated facial droop

mild hemisensorimotor loss or ataxia

very mild cortical hand weakness (especially nondominant)

isolated mild aphasia

thrombolysis evidence:

no clear benefit of intravenous thrombolysis with alteplase/tenecteplase (PRISMS/TEMPO-2 trials)

the ARAMIS trial showed dual antiplatelet therapy (aspirin+clopidogrel) noninferior to alteplase for excellent 90-day outcomes in nondisabling minor stroke, with superior safety (less bleeding than alteplase 0.3% vs 0.9%)

these patients require intensive neuro-monitoring (e.g., q15min checks), and if they deteriorate (early neurologic deterioration - END), intervene immediately (urgent reassessment/repeat imaging/recanalization procedure)

if large vessel occlusion (LVO) is present, discuss IVT and/or thrombectomy even with low NIHSS (you are not treating the current symptoms; you are treating the impending disaster)

19/02/2026

New timings of OPd for the Month of Ramadan.

06/02/2026

Migraine Variants –
Full Presentation and Diagnostic Criteria (ICHD-3)

1) Familial Hemiplegic Migraine (FHM)
Full clinical presentation

Recurrent migraine attacks with aura including motor weakness
Aura symptoms (reversible):
Motor: unilateral hemiparesis (defining feature)
Visual: scintillations, scotoma
Sensory: paresthesia, numbness
Speech/language: dysarthria, aphasia
Aura may develop gradually and last longer than typical migraine aura
Severe migraine headache follows aura
Associated symptoms: nausea, vomiting, photophobia, phonophobia
Between attacks: normal neurological examination
Possible complications: prolonged weakness, seizures, coma (rare)

ICHD-3 diagnostic criteria (summary)
At least 2 attacks fulfilling migraine with aura criteria
Aura includes fully reversible motor weakness
Aura includes at least one of:
Visual
Sensory
Speech/language symptoms
At least one first- or second-degree relative with similar attacks
Not better explained by another diagnosis

2) Migraine with Brainstem Aura (Basilar Migraine)
Full clinical presentation
Recurrent migraine attacks with brainstem aura symptoms
Aura symptoms (fully reversible):
Vertigo
Dysarthria
Diplopia
Tinnitus
Hypacusis
Ataxia
Decreased level of consciousness

Symptoms are bilateral
Followed by occipital or diffuse migraine headache
Associated migraine features: nausea, vomiting, photophobia, phonophobia
Neurological exam normal between attacks
ICHD-3 diagnostic criteria (summary)
At least 2 attacks fulfilling migraine with aura criteria
Aura includes at least 2 brainstem symptoms
No motor weakness
No retinal symptoms
Aura symptoms are fully reversible
Not better explained by another diagnosis

3) Periodic Syndromes Associated with Migraine (Childhood Migraine Equivalents)
Full clinical presentation
Recurrent, stereotyped episodic symptoms
Complete return to baseline health between episodes
Headache often absent or minimal
Strong personal or family history of migraine
Frequently evolve into typical migraine later in lifeA) Abdominal Migraine
Presentation
Recurrent episodes of midline or periumbilical abdominal pain
Moderate to severe intensity
Associated with:
Anorexia
Nausea
Vomiting
Pallor
No headache during attacks
Symptom-free intervals
ICHD-3 criteria (summary)
At least 5 attacks
Pain lasts 2–72 hours
At least 2 associated symptoms
Normal evaluation
Not explained by another disorder

B) Benign Paroxysmal Vertigo of Childhood
Presentation
Sudden recurrent episodes of vertigo
Occurs in young children
Associated:
Nystagmus
Ataxia
Pallor
Vomiting
Consciousness preserved
Normal exam between attacks
ICHD-3 criteria (summary)
At least 5 attacks
Sudden onset vertigo lasting minutes to hours
Normal neurological exam between episodes
Not due to another disorder

C) Benign Paroxysmal Torticollis of Infancy
Presentation
Recurrent head tilting episodes
May alternate sides
Associated:
Vomiting
Pallor
Irritability
Ataxia
Onset in infancy
Normal development between attacks
ICHD-3 criteria (summary)
Recurrent stereotyped episodes
Onset in infancy
Complete resolution between episodes
No alternative diagnosis

D) Infantile Colic (Migraine association)
Presentation
Recurrent prolonged crying episodes in infants
Occur in otherwise healthy infants
Associated with later development of migraine
Diagnostic note
Recognized as a migraine-related condition, not a primary headache disorder

29/01/2026

Diffusion Restriction in Brain MRI
1. Fundamental Concept
Diffusion restriction refers to the reduction of water molecule mobility within tissues, typically due to cytotoxic edema (cellular swelling) or high cellular density. On MRI, this is primarily evaluated using Diffusion-Weighted Imaging (DWI) and quantified via the Apparent Diffusion Coefficient (ADC).
2. Imaging Appearance
DWI: Restricted diffusion appears bright (hyperintense).
ADC map: Restricted diffusion appears dark (hypointense) because ADC values are low.
T2 shine-through: Bright DWI signal without true restriction (high T2 signal mimicking restriction) can be distinguished by confirming low signal on ADC maps.
3. Major Clinical Applications
A. Acute Ischemic Stroke
Hallmark finding: Restricted diffusion appears within minutes of arterial occlusion.
Mechanism: Cytotoxic edema → failure of Na⁺/K⁺ ATPase pump → water shift into cells.
Evolution: ADC declines for 3–5 days, pseudonormalizes at ~7–10 days, then increases (chronic gliosis/encephalomalacia).
B. Infections
Pyogenic abscess: Restricted diffusion in central pus (viscous fluid, inflammatory cells).
Encephalitis (e.g., herpes simplex): Often shows cortical diffusion restriction.
Tuberculomas/CREUTZFELDT-JAKOB DISEASE (CJD): Cortical and deep gray matter restriction (CJD classic: cortical ribboning and pulvinar sign).
C. Neoplasms
High-grade tumors (e.g., glioblastoma, CNS lymphoma): Often show restricted diffusion due to high cellularity.
Epidermoid cysts: Show marked restriction (mimic CSF on T2 but bright on DWI).
Differentiation: ADC values can help differentiate lymphoma (very low ADC) from glioblastoma or metastasis.
D. Demyelinating Disease
Acute MS plaques: May show peripheral restriction (hypercellular inflammatory edge).
Progressive multifocal leukoencephalopathy (PML): May show subtle white matter restriction.
E. Traumatic Injury
Diffuse axonal injury (DAI): Restricted diffusion in white matter tracts.
Acute contusions: Cytotoxic edema ± hemorrhage.
F. Seizure-related Changes
Postictal changes: Transient cortical restriction due to excitotoxic edema.
Status epilepticus: May show cortical/subcortical restriction.
G. Toxic/Metabolic Conditions
Hypoglycemia, carbon monoxide poisoning, osmotic myelinolysis: Can involve deep gray matter or white matter.
Posterior reversible encephalopathy syndrome (PRES): Usually no restriction (vasogenic edema); if present, may indicate infarct.
4. Quantitative ADC Values
Normal brain parenchyma: ADC ~800–1000 × 10⁻⁶ mm²/s.
Acute infarct: ADC often

28/01/2026