NEUROLOGY PROBLEMS – DIAGNOSTIC CHALLENGES · LP – wbc

NEUROLOGY PROBLEMS – DIAGNOSTIC CHALLENGES

Dr Ben Turner Barts Health NHS Trust London Bridge Hospital

Thunderclap Headache

!  Subarachnoid haemorrhage !  Other vascular events - AVM, mass lesion,

GCA, hypertension, dissection, cerebral venous thrombosis

!  Pituitary apoplexy !  Meningitis !  Exertional headache (sex, gym) !  Migraine !  Idiopathic

Subarachnoid haemorrhage


!  6 / 100,000 - annual incidence !  1 / 4 of sudden onset headache !  1 / 8 of isolated sudden headache !  defining sudden onset - ‘hit by a sledge-hammer’ !  arising in seconds, within a few minutes lasting > 1 hour !  community study of sudden onset headache <1 minute and

lasting >1 hour 37 / 148 (25%) had SAH !  more likely with assoc features, nausea, vomiting, neck

stiffness, transient loss of consciousness, focal neurological features


!  CT scan – 98% < 12 hours, 93% < 20 hours !  LP – xanthochromia develops after 12 hours ,

remains for ~ 2 weeks !  Spectrophotometry for bilirubin (only made in

vivo) and oxyhaemoglobin

CT scans in A&E: false reassurance

!  Cerebrovascular - Subarachnoid haemorrhage (SAH) -  arterial dissection -  cerebral venous sinus thrombosis -  CNS vasculitis (Temporal arteritis) !  Meningoencephalitis !  Tumours -  posterior fossa, pituitary, leptomeningeal !  Low intracranial pressure

Case 1 – worse headache ever

!  56 year old female !  History of occasional migraine !  2 day before presentation, nausea for 30 mins

then vomited, followed by abrupt (< 1 minute) onset severe headache, extended to neck, eased after 2 hours, then recurred today, then residual headache 6/10, throbbing, BP 160/90mmHg

!  Had been using nasal decongestants last few weeks

!  Subsequent 2 – 3 episodes of ‘thunderclap’ headaches

!  Some nausea, no photophobia, mild neck stiffness

!  No focal neurology or seizures

Case 1 – worse headache ever

!  No fever, hypertension, no neurological signs !  Bloods normal, no raised inflammatory

markers !  CT brain – normal !  LP – wbc <1, RBC 702 / 486, protein 430mg/lL but raised bilirubin !  CT cerebral angiogram

Reversible Cerebral Vasoconstriction Syndrome (RCVS)

!  Severe headaches with or without seizures or focal neurological deficits

!  Transient disturbance in the control of cerebral vascular tone leading to multifocal arterial constrictions and dilatations

!  Resolves in 1 -3 months !  20% cortical SAH, 10% ischaemic or

haemorrhagic CVA


!  Incidence unknown !  Females > males, 13 -70yrs, mean 45 yrs !  60% secondary; 1.  postpartum, 1st week, 60% assoc with

vasoconstrctors 2.  vasoactive substances, ergotamine to OTC

sympathomimetics (nasal decongestants) 3.  SSRI 4.  recreational drugs – cannabis, cocaine


!  Multiple ‘thunderclap’ headaches suggestive !  Usually over 7 days, then constant for 3 weeks !  haemorrhage early in first 7 days, infarction in

second week !  Triggers reported in majority, sex, coughing etc !  CT cerebral angiogram 80% sensitive, but may be

normal in first 4 days !  CSF may be abnormal with pleocytosis and ↑protein

!  Treatment - nimodipine IV or 60mg 4 hourly

NEUROLOGY PROBLEMS – DIAGNOSTIC CHALLENGES

Dr Ben Turner Barts Health NHS Trust London Bridge Hospital

Case 2 Tingling and unsteady

!  21 year old female !  Gastrointestinal upset then.. !  2 week history of paraesthesia hands and feet !  Vitamin B12 low normal – given replacement !  Continued progression with ascending

paraesthesia and unsteadiness !  Areflexia with loss of vibration and joint

position sense, Romberg’s positive, no weakness


Differential Diagnosis !  Guillain Barre Syndrome !  Vitamin B12 deficiency !  myelitis (posterior) !  Compressive myelopathy !  Paraneoplastic syndrome !  Vitamin E deficiency





Nitrous Oxide Myeloneuropathy

Nitrous oxide is an inhaled anaesthetic drug which irreversibly oxidizes the cobalt ion of cobalamin (vitamin B12) from the (+) 1 to the (+) 3 valence state. Oxidation of the cobalt ion by nitrous oxide prevents methylcobalamin from acting as a coenzyme in the production of methionine and subsequently S-adenosylmethionine, which is necessary for methylation of myelin sheath phospholipids. The result is decreased myelin formation.



NO and Vitamin B12

!  15 % > 65 years are Vitamin B12 deficient !  Megablastic anaemia is inverse to neurology !  20% of B12 is bound to transcobalamin

(active) !  Methylmalonic acid levels may be indirect but

superior marker of B12 status, homocysteine also but less specific

!  Subacute combined degeneration of spinal cord (SACD) occurs typical 2 – 6 weeks after exposure from anaesthetic

NO and Vitamin B12

!  Clinical Presentation !  Loss of posterior column modalities –

proprioception and vibration sense (a sensory ataxia), L’hermitte’s phenomenon, optic neuropathy

!  Can progress to weakness, incontinence, pyramidal signs – extensor plantars

!  Demyelination of posterior and lateral spinal columns and demyelinating / axonal neuropathy

!  Treatment – parenteral hydroxocobalamin 1mg im alternate days, until improvement

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NEUROLOGY PROBLEMS – DIAGNOSTIC CHALLENGES · LP – wbc