Neurology 3 Flashcards
Dying forward hypothesis means?
Dying backward hypothesis means?
Forward - glutamate toxicity - degeneration of anterior motor horn
Backward - starts degeneration at muscle/Neuromuscular junction
Splint hand syndrome in motor neuron? - what muscles wasted?
Thenar and 1st interossei muscle wasting
Clinical features of Motor neuron disease?
Asymmetrical weakness in either distal/proximal
Fasciculations
Pseudobulbar (UMN) symptoms
Respiratory dysfunction
NO SENSORY INVOLVEMENT
Investigations in MND shows?
Normal conduction studies
- Reduced CMAP
- Normal SNAP
EMG - fasciculations, fibrillations
MRI - corticospinal hyperintensity
Holmes tremor ( Resting + Action + intentional tremor) where is the lesion?
midbrain tegmentum outside of red nucleus
What is dystonia?
intermittent/sudden muscle contractions - twisting/torticollis
What is Positive myoclonus and negative myoclonus?
Fastest/brief sudden increase in tone
Negative myoclonus - decrease in tone due to Ammonia/CO2
What is dyskinesia?
Overactivity movement
why cogwheel rigidity occurs?
Tremors superimposed on increased tone
REM sleep disorder is marker of what?
Poorer outcome for dementia
Only Alpha synuclein can cause it!
Motor fluctuations in PD occurs when?
After > 2 years -on conventional therapy + higher levodopa dose
Longer duration of PD ( younger patients)
What to watch out if give MAOB inhibitors?
MAOB inhibit MAOB and MAOA
- MAOA breaks down noradrenaline ( from tyramine)
- so no MAOA = adrenergic crisis
Treatment for motor fluctuations?
Break down dose to increase frequency
Add COMT inhibitors
What sign is often indicator of advanced dementia?
What is strongest predictor of dementia?
Visual hallucinations
Age
Fragile X syndrome - how many nucleotide expansion before gene is ‘turned off’ - problematic?
Premutation syndrome - how many nucleotide expansion?
200 CGG repeats = FMR1 protein deficiency causing Fragile X syndrome ( intellectual disability/seizures) or FXTAS
> 40, < 200 CGG repeats = Premutation syndrome ( Primary ovarian insufficiency/ Neurodevelopmental delays and psychiatric disturbances) or FXTAS
Huntington disease - HTT protein toxic to what in brain?
Striatal neurons
What is Westphal Variant?
Huntington manifestation < 20 yrs. CAG > 55
Commonest organism to cause rhomboencephalitis?
Listeria
Epilepsia partialis continua/kojevnikov epilepsy is pathognomic for?
HSV encephalitis
seizure every seconds to minutes hence PLEDS
Herpes simplex PCR from CSF accuracy?
High sensitivity and specificity but can be negative first 24 hours
Metagenomic next generation sequencing good for?
Detect virus antigen from RNA/DNA in CSF ONLY
Paraneoplastic Encephalitis - mediated by? prognosis?
Autoimmune encephalitis - mediated by? Prognosis?
Paraneoplastic - T cell mediated = intracellular antigen = poor prognosis
*ANTIBODIES ARE BYSTANDER AND A/W MALIGNANCY SO MUST CHECK FOR IT
Autoimmune - B cell mediated = extracellular/surface antigen = good prognosis
Paraneoplastic antibodies and a/w encephalitis?
anti-HU = SCLC ( Limbic encephalitis)
Anti-YO = Breast/ovarian cancer ( Cerebellar degeneration)
anti-Ri =opsoclonus myoclonus ( Rhomboencephalitis)
Anti-Ma = Testicular cancer (Rhomboencephalitis)
HSV encephalitis goes on to develop what autoimmune encephalitis?
NMDA encephalitis
Commonest autoimmune encephalitis and pathognomonic symptoms?
NMDA encephalitis
have preceding viral flu syndrome
NMDA treatment?
Remove cancer
Give IV methylprednisolone then oral prednisolone
IVIG/ plasmapheresis
PRES syndrome MRI shows?
Posterior circulation edema and increased hyperintensity
Injury in spiral groove - signs?
Injury above spiral groove - signs?
In spiral groove - Brachioradialis weakness, wrist and finger EXTENSION weakness
Above spiral groove - no triceps support = elbow extension weakness
Sensory pattern
-high lesions affecting radial nerve = where is numbness?
-low lesions ( past posterior cutaneous nerve of forearm) affecting radial nerve = where is numbness?
- entire dorsal lateral arm ( towards thumb side)
2. Dorsal part of hand ( thumb till half of 4th digit)
Brachioradialis innervated by what nerve root?
C5/6
PSP sign means?
Midbrain atrophy without pontine involvement
Withdrawing Levodopa abruptly causes?
Akinesia
Neuroleptic malignant syndrome!!
Side effects of Dopamine replacement therapy?
Dyskinesia as dopamine absorbed erratically from GI tract
Side effects of Levodopa?
Peripheral neuropathy
Dopamine dysregulation syndrome
Benign course of parkinson indicators?
Female
Tremor predominant
Earlier onset
