Ocular neuromyotonia

Ocular Neuromyotonia
Kenneth Ricker (1935–2004) (photo)
Hans Georg Mertens (1921–2006) 

Definition
"intermittent, tonic spasms of one or more of the EOM, resulting in strabismus & paroxysmal diplopia"
-delayed relaxion of EOM makes eye temporarily get 'stuck' after eccentric gaze
- AKA "locking-eye"
Etiology
-MC post-RXT of parasellar area
> 2 monhts to 18 years, mean 5y
-Others: autoimmune disorders (MG & thyroid disease)
-Rare: chemotherapy(cisplatin, 5-FU), Vit B12/D def, thorium myelography, botox injection, alcohol, and cataract surgery

Pathophysiology
-May relate to focal demyelination causing ephaptic transmission
-Eggenberger suggest “reflecting nerve circuit”
-Dysfunction of potassium channels
-Mucopolysaccharide deposition after thyroid-associated orbitopathy

Presentation
-Transient diplopia/strabismus

Neuro-exam
-Prolonged eccentric gaze (1 min)
-Advanced test: electromyography, electrooculography, and videotaping 

Investigation
-bMRI and oMRI w/wo contrast
-TFT

Ddx
-ONM = Triggered by sustained eccentric gaze + brief tonic deviation
-SOM = Torsional micro-oscillations (tremor)
-Cyclic 3rd = Cyclic (predicted) weakness/spasm in a fixed rhythm
-Convergence spasm = Miosis + accommodation
-MG = Fatigues
-Graves = Restrictive pattern + orbital signs
-Decomp phoria = Fatigue‑dependent misalignment without spasm

Therapy
-Carbamazepine & oxcarbazepine
*lower dose
-Others: gabapentin, phenytoin, lacosamide
-Tx hypovitamins
-If refractory, surgery→ binocular fusion w/ strabismus surgery
-Behavioral change, if pt has a AM clock to one side change to other

Videos

ONM
-Nasopharyngeal CA, ttx w/ cisplatin + 5-FU, 9y later transient diplopia
*Worse w/ prolonged eccentric gaze
-Tx CBZ

ONM
-Midbrain glioma, RXT 20y before, now R CN III palsy
-ONM observed during ptosis surgery
ONM
-Full resolution within 1y
-Difficult to atrtibute only to ONM
>Pt does not have tonic spasm
ONM
-Remote hx of pituitary macroadenoma
-Referral for intermittent diplopia for several years

Neurobowl - 2026

Neurobowl - 2026

1️⃣ Video w/ FBDS
A definitive serum diagnostic study was performed. 
Her serum demonstrated _____   ____
LGI-1 antibody

This patient likely has what electrolyte abnormality?
Hyponatremia

2️⃣ Pt w/ clivus chordoma, treated w/ surgery and radiation. 5y later, p/w R CN VI palsy, which was not really palsy was myotonia
Ocular neuromyotonia
-Tx CBZ/OXC

3️⃣ Severe R&L M1 stenosis
This patient's diagnosis is ______ syndrome
-moyamoya
-RNF213 gene

4️⃣ 66yo woman w/ small prior stroke and acute onset dysarthria and dysphagia
-Pseudobulbar palsy
-Foix-Chavany-Marie syndrome

5️⃣ Video w/ stroke pt w/ mouth and genital ulcers
This pt most likely diagnosis is ____
-Behcet
-Cascade sign aka waterfall sign
6️⃣ Hands dark rash, uveitis, and headaches
-VKH (Vogt-Koyanagi-Harada) syndrome
-BEE→ Brain, Ear, Eye
-T-cell autoimmunity targeting melanocytes

7️⃣Video w/ pt closing and having difficult to open hand
She reproted that did not worse with sustained activity
-Myotonia congenita
8️⃣11yo boy w/ abnormal movements occuring when going to the chalkboard 
PKD
-PRRT2

9️⃣This best term for this patient's clinical symptoms is _______
Amusia
"tone-deafness"
Does not recognized tones, you can try happy birthday

1️⃣0️⃣
Brain abscess p/w aphasia
Tongue w/ telangiectasia
Intrapulmonary shunt
Osler Weber Rendu syndrome
Hereditary hemorrhagic telangiectasia

Neurobowl - 2025

Neurobowl - 2025

1 - Stroke, bMRI w/ WMD, skin biopsy w/ lipoma
CADASIL
Notch3

2 - Hemichorea
Subthalamic nucleus (Nucleus of Luys)

3 - JME
EEG: Generalized 4Hz spike-and-wave discharges induced by photic stimulation

4 - Thetered cord
Spinal cord ends around L1/2

5 - West Nile virus

6 - TGA

7 - Frey's syndrome
Cause by parotidectomy
Damage auriculotemporal nerve, which conveys autonomic fibers from the glossopharyngeal nerve

8 - Post-LP headache 2/2 epidural
Pneumocephalus
Intracranial hypotension

9 - Meige syndrome

10 - Peter Brueghel

11 - Melkersson-Rosenthal syndrome
-Lingua plicata 

12 - Pseudogout
Rhomboid-shaped crystals
Polarized light

13 - I-CAA
Inflammatory-CAA

14 - Vogt Koyangi Harada disease
T-cell-mediated autoimmunity targeting melanocytes

15 -  

Neurobowl - 2024

Neurobowl - 2024

1. Silas Weir Mitchell
-Discoverer of the phantom limb

2. ⁠Right sciatic nerve causing a foot drop

3. Left dorsal pons
4. 8 and a half syndrome
1 + 1/2 + CN 7 = 8 and 1/2

5. Nitrous oxide leading to a myelopathy

6. Dural AV fistula

7. DYT1 Dystonia, not dopamine responsive 
-TorsinA
-Showing a child w/ leg involvement, and significant improvement after DBS
8. Cheiro oral syndrome

9. X linked adrenoleukodystrophy
-accumulation of VLCFAs
-defect ABCD1→ impair peroxisomal β‑oxidation→ VLCFAs accumulate

10. Myokymia and 11. Radiation plexitis
- lung cancer w/ radiation 8y before
- now brachial plexus distribution myokymia

12. ALS with Stephen Hawking

13. Locked in syndrome
Movie: The Diving Bell and the Butterfly
14. Marginal mandibular branch of the facial nerve injured during surgery

15. Eastchester Clapping Sign
-Hemispatial neglect
-Eastchester High School
16. Dermoid cyst
Epidermoid cyst→ Restricts on diffusion; not T1-bright
Lipoma→ Pure fat, usually no calcifications or heterogeneous contents
Arachnoid cyst→ CSF intensity across all sequences, no fat
Teratoma→ Contains fat + soft tissue + calcifications; more complex

17. Facioscalpohumeral dystrophy and 
18. beevor sign
“movement of umbilicus in supine attempting to flex the head”
19. Post fixational blindness in bitemporal hemianopia


Kahoot

Kahoot!
-QoD

AIS Guideline 2018-2026

AIS Guideline 2018-2026

What Really Changed?
Based on Prabhakaran et al. (2026)
2026 Guideline for the Early Management of Patients With Acute Ischemic Stroke: A Guideline From the American Heart Association/American Stroke Association

IVT
Thrombolytic Agent
2018: Alteplase only (standard 0.9 mg/kg)
2026: Tenecteplase (0.25 mg/kg) or alteplase — both Class I recommended
*Tenecteplase 1st-line, if LVO bridging therapy, patients requiring rapid workflow, difficult IV access or prehospital administration
NIHSS and Disability
2018: NIHSS severity emphasized
2026: Any disabling deficit should receive IVT — NIHSS alone should not delay therapy
Ex: aphasia, hemianopia, dominant-hand weakness

Non-disabling stroke
2026: IVT not recommended; DAPT preferred
Extended Window
2018: Mainly MRI DWI–FLAIR mismatch (“wake‑up stroke”)
2026: Perfusion-based IVT up to 9 hours, including wake-up/unknown onset strokes
-CTP
-bMRI D/H: DWI lesion involving <1/3 of MCA territory with no FLAIR signal changes
Contraindication
-prior ICH, DOAC exposure, and stroke within the past 3-months are now relative contraindications
sICH after IVT
EVT
Time Window
2018: 0–6 hrs standard; 6–24 hrs selective (DAWN/DEFUSE‑3)
2026: 0–24 hrs broadly accepted with imaging selection

Large Core Infarcts
2018: Mostly excluded
2026: ASPECTS 3–5 recommended; even 0–2 reasonable in select cases (Class IIb)
>Supported by RESCUE‑Japan, SELECT2, ANGEL‑ASPECT data

Posterior Circulation
2018: No strong recommendation
2026: Class I recommendation for basilar artery thrombectomy (≤24 hrs)
>Supported by ATTENTION & BAOCHE

Pre-stroke Disability
2026: mRS 2 patients now included

Pediatric EVT (NEW)
≥6 years: Class IIa
<6 years: Class IIb selected cases
First formal pediatric interventional guidance
Pediatric AIS
Imaging
-MRI/MRA preferred, but if MRI cannot be obtained within 25 minutes, use CT/CTA to evaluate for LVO

Treatment
-IV alteplase: May be safe, but efficacy remains unclear
-EVT in pediatric LVO (see above)

Early BMT
Glycoprotein IIb/IIIa inhibitors
-No established benefit for IV tirofiban
-IV abciximab is discouraged

Oral anticoagulation
-Early initiation reasonable for mild strokes with Afib

Post‑EVT BP management
-Avoid intensive SBP <140 immediately after thrombectomy

DAPT
-Now recommended for patients presenting within 72h, NIHSS ≤5, and suspected atherosclerotic disease
https://live.avomd.io/algo/01542d1291e749fca1

Remaining gaps
-EVT for NIHSS ≤6
-Optimal intra‑arterial thrombolysis dosing

EEG - Delta wave

Delta Wave

Denition
-Frequency: <4 Hz
-Physiology: Large‑amplitude, slow oscillatory activity

Mechanism
-2 major neuronal generators:
>Thalamocortical networks→ synchronous, rhythmic delta (particularly in sleep)
>Intrinsic cortical circuits→ focal, polymorphic delta (often pathological)
-Modulators:
>Glial/astrocytic networks influence slow oscillations
*Delta is never generated by purely neuronal mechanisms

Interpretation 
-Depends age, vigilance state, topographic distribution, morphology, reactivity, and clinical context

Age
-Infancy: abundant delta→ physiologic
  ~10 years: <10% of background
-Adults: largely absent in awake state
-Elderly: up to ~1% may persist as physiologic

State
-Delta↑ w/ ↓alertness
>Drowsiness: ↑, often temporal
-Hyperventilation: ↑ generalized delta
-N3 sleep: high‑amplitude, synchronous, generalized delta (“slow‑wave sleep”)

Topography and morphology
-Polymorphic focal delta
>Persistent, non‑reactive, state‑independent→ strong marker of structural lesion (subcortical lesions or large cortical lesions)

-Generalized polymorphic delta
>Suggests diffuse encephalopathy

Rhythmic patterns
-FIRDA (Frontal Intermittent Rhythmic Delta Activity)
>Bilateral, symmetric, intermittent rhythmic delta
>Associated w/ diffuse cerebral dysfunction, ↑ICP, or metabolic encephalopathy
>Benign in children/teens

-TIRDA (Temporal Intermittent Rhythmic Delta Activity)
>Focal, typically unilateral
>Associated w/ TLE, even w/o interictal spikes

-OIRDA (Occipital Intermittent Rhythmic Delta Activity)
>Mainly in children
>Associated w/ CAE and others idiopathic generalized epilepsies

-LRDA (Lateralized Rhythmic Delta Activity)
>Critically ill patients
>IIC pattern

-GRDA  (Generalized Rhythmic Delta Activity)
>Seen in: encephalopaty, sedation,  post‑anoxic injury
>Not epileptiform unless evolving

-SIRPIDs  (Stimulus‑Induced Rhythmic, Periodic, or Ictal‑appearing Discharges)
>Often rhythmic delta following stimulation
>Occur in comatose, septic, or anoxic patients
>Falls under IIC spectrum

-Delta brush pattern
>Fast activity riding on delta
-Seen in: Anti‑NMDA encephalitis (extreme delta brush), premature neonates (physiologic delta brush)

Clinical significance
-Excess generalized delta→ diffuse encephalopathy
-Focal persistent delta→ structural pathology
-Intermittent rhythmic delta→ epilepsy or prior brain injury (location matters)
>Temporal→ TLE
>Occipital→ CAE
>Frontal→ diffuse dysfx

Clinical pearl
-Delta alone is never inherently normal or abnormal — context determines meaning
-Persistent focal polymorphic delta has the highest specificity for structural lesions
-Rhythmic delta is more associated with epilepsy or IIC than polymorphic delta
-Non‑reactive generalized delta in an awake adult→ think encephalopathy

Nodo‑Paranodopathy

Nodo‑Paranodopathy

"My AIN, PAIN"

History
1990s Anti-GM1, paradox of electrical demyelination w/ axonal integrity
2012-2013 Uncini & Kuwabara, term nodopathy
2021 EAN guidelines AIN≠CIPD

Pathophysiology
-AIDP/CIDP = macrophage btw myelin lamellae→ T‑cell recruitment→ segmental demyelination
>Schwann cells shift into iDSc (mimicry)
>AKA macrophage‑associated demyelinating (MAD)-neuropathy
>Demyelination = temporal dispersion + conduction block caused by segmental myelin loss

-NP = Ab-mediated
>Start paranodal loops
>AKA pure antibody‑induced neuropathy (AIN-PAIN)
>Reversible conduction failure (RCF)
  RCF = nodal dysfunction w/o structural injury
Localization
-Node (Kv7)
>NF‑186 (often severe and fulminant)

-Paranode
>NF‑155 (classically tremulous phenotype)
  Triad: Young + ataxic + tremulous
  
>CASPR1
>Contactin‑1 (CNTN‑1) (classically edematous phenotype)
  Triad: Elderly + aggressive + edematous
  Assoc w/ membranous glomerulopathy

-Juxtaparanode (Kv1)
>CASPR‑2
>LGI4
PAIN
-2 types = ganglioside & nodal

Ganglioside Ab
-Usually transient
-Typically produce AIDP presentations
-Often reversible

Nodal Ab
-AIDP/CIDP-like
- AIDP-like: RFC; if early, complete recovery
>Severe cases (like IgG3) activate MAC; irreversible

Acute vs. Chronic
-concept  of IgG class switch
Acute Phase
-Driven by short‑lived plasmablasts
-IgG3 Ab→ ⊕complement (fulminant damage)
Chronic Phase
-Maintained by long‑lived plasma cells
-switch to IgG4 Ab→ ⊖complement; act as functional blockers
*smoldering neuropathy

Therapy
Seropositivity matters for treatment choice
-RTX→ effective IgG4 disorders
-IVIG→ less effective in IgG4
>IVIG relies on complement inh

Consider Ab-test if:
-tremor, ataxia, speed (aggressive), resistance (IVIG), comorbidies (GN), pain

Summary
-First-line
>RTX for NF155, CNTN1, CASPR1 (IgG4/IgG3)
>IVIG/PLEX for ganglioside-mediated AIN, CASPR2

-Second-line
>Combination RTX + IVIG for overlap or refractory cases

Epileptiform Discharge

Epileptiform Discharge
According to IFCN, a waveform can be considered epileptiform if ≥4 of 6 defining features are present:

1️⃣ Physiological field of distribution
-The discharge must have a plausible neurophysiological field.
-It should show:
>A clear phase reversal
>A logical spatial voltage gradient
>Distribution consistent with cortical generators
This helps differentiate true cortical discharges from artifact or benign variants

2️⃣ Morphology: spike or sharp wave
-The waveform must have the morphology of:
>Spike: duration < 70 ms
>Sharp wave: duration 70–200 ms
These reflect synchronous neuronal depolarization

3️⃣ Asymmetry of the waveform
-The ascending limb is steeper and more vertical
-The descending limb is slower and less steep
This asymmetry distinguishes epileptiform discharges from benign rhythmic activity

4️⃣ After-Coming Slow Wave
-A true epileptiform discharge is often followed by a slow wave
-This represents:
>Spike → depolarization
>Slow wave → inhibitory postsynaptic potentials/repolarization
The slow wave reinforces epileptogenic significance

5️⃣ Duration Different from Background
-The waveform should have a clearly different duration from surrounding background rhythms
-It should stand out from alpha, theta, or delta activity
This ensures it is not a fragment of background oscillation

6️⃣ Disruption of Background Activity
-The discharge should interrupt or distort ongoing background rhythms
-There may be:
>Transient attenuation
>Phase resetting
>Background interruption
This indicates abnormal cortical synchronization

Locked-In Syndrome

Locked-In Syndrome

SPT
Communicationg strategies

Low‑Tech AAC
-Early on during acute and subacute rehab
 If look to all directions→ transparent board
 If only up/down→ technique (go by line, and then letter)
>Eye‑blink systems (1 blink = yes, 2 = no)
>Eye-gaze boards (alphabet boards, color-coded grids)
>Partner-assisted scanning
>Simple speech-generating switches, if any movement available (e.g., toe, finger, head, eyelid)

High‑Tech AAC
-Stable eye movement or small residual motor control
>Eye-tracking communication devices (e.g., Tobii Dynavox, EyeLink)
>Brain–Computer Interface (BCI) systems (experimental but promising)
>Speech-generating AAC tablets

Subscribe to: Comments (Atom)