More neuro Qs Flashcards
Name all 4 clinical courses of MND and what part of the CNS they affect and therefore what symptoms develop
- ALS - Amyotrophic Lateral Sclerosis: UMN + LMN
Disease of lateral corticospinal tracts, cause weakness with UMN signs and LMN wasting; progressive spastic tetraparesis with LMN signs and fasciculation - PMA - Progressive Muscular Atrophy: LMN ONLY
Wasting begins in muscles of hands and spreads to anterior horn cells; no UMN signs; lost reflexes and widespread wasting and weakness - PBP - Progressive Bulbar Palsy: UMN & LMN OF LOWER CRANIAL NERVES
Affects cranial nerves 9 – 12, develop dysarthria, dysphagia, and nasal regurgitation of fluids and choking, can be mixed UMN/LMN signs, progresses to ALS - PLS - Primary Lateral Sclerosis: UMN
Loss of Betz cells in motor cortex, mainly UMN signs, progressive tetraparesis with terminal pseudobulbar palsy
Regardless of the body part that is first affected by ALS disease, weakness and
atrophy spread to other parts of body with varying degrees of upper motor
neuron (UMN) symptoms (e.g., spasticity) and eventually involve the muscles
of all 4 extremities and the trunk, as well as bulbar muscles.
Rectal and bladder sphincters and oculomotor muscles are usually spared.
No sensory symptoms.
Gene associated with MND
SOD1
What is the El Escorial Criteria?
El Escorial Criteria for the diagnosis of Amyotrophic Lateral Sclerosis
The diagnosis of ALS requires the presence of:
- Signs of lower motor neuron (LMN) degeneration by clinical, electrophysiological or neuropathology examination,
- Signs of upper motor neuron (UMN) degeneration by clinical examination, and
- Progressive spread of signs within a region or to other regions,
together with the absence of:
Electrophysiological evidence of other disease processes that might explain the signs of LMN and/or UMN degenerations; and
Neuroimaging evidence of other disease processes that might explain the observed clinical and electrophysiological signs.
Probable = LMN and UMN signs in 2 regions
Probably + lab support = LMN and UMN signs in 1 region
Suspected = LMN or UMN signs in 1 region
Tx of MND
- Riluzole - supresses glutamate activity
- MDT approach – Neurologist, speech and language therapists, occupational therapists, Specialist Nurse, Physiotherapist etc.
- Symptomatic: e.g. baclofen for spasms, Non-invasive ventilation when needed, PEG tube for feeing when needed
UMN SX
Weakness Brisk reflexes Hypertonia Upgoing Plantars (positive Babinski) Clonus
LMN SX
Weakness Depressed/Absent reflexes Decreased tone Wasting Fasciculations
What organisms may trigger Guillian-Barre syndrome?
Campylobacter jejuni, CMV, Mycoplasma,
Zoster, EBV, HIV but no obvious infectious cause is found in 40%
What symptoms are seen in Guillian-Barre syndrome?
- 1-3 weeks post infection: symmetrical, ascending muscle weakness.
(can advance quickly and cause total paralysis) and/or numbness - Weakness begins in distal limb muscles and progresses to more
proximal muscles over 4 weeks - recovery follows this - Loss of reflexes, neuropathic pain and autonomic dysfunction
(sweating, tachycardia, arrhythmias) - In 20%, respiratory muscles and facial muscles are affected respiratoy involvement requires ITU admission.
What Ix for Guillian-Barre syndrome?
- Confirmed with nerve conduction studies (slow nerve conduction, and
prolonged distal motor latency +/- conduction block) - Lumbar Puncture: CSF- increased proteins, WCC normal
- Consider spirometry to monitor FVC - a decreased forced vital
capacity can indicate the need to admit to ITU to maintain airways.
Mx of Guillian Barre?
IV immunoglobulin (IVIg) for 5 days: decreases duration and severity of paralysis. Plasma exchange also effective but seldom used.
24 Monitor ventilation. Ultimately self-limiting but need to prevent respiratory
failure.
Encephalitis - what can cause?
Viral infection
- Herpes simplex virus 1 + 2 (most common cause in the UK), Varicella zoster virus, Epstein Barr, Cytomegalovirus, HIV, Mumps,
Measles
Non-viral causes – secondary to bacterial meningitis, TB, toxoplasma, malaria, listeria, Cryptococcus etc.
What is encephalitis?
Infection and inflammation of the brain parenchyma.
Risk Factors: Extremes of age, and immunocompromised patients
Pathophysiology: disease which mostly affected the frontal and temporal
lobes, so causes decreased consciousness, confusion, and focal signs
Clinical features of encephalitis
- Begins with features of a viral infection
- Fever, headache, myalgia, fatigue, nausea. - Progresses to
- Decreased consciousness/confusion, drowsiness
- Behavioural change
- Focal Neurological Deficit
- Seizures
- Coma - May have signs of meningitis (meningo-encephalitis= inflammation of
the brain lining + parenchyma)
Diagnosis of encephalitis
- LP (cultures + PCR study, moderate increase in protein level , lymphocytes, +/- decreased glucose)
- Others : FBC and blood film- leucocytosis
- Blood cultures, Viral PCR, U+E’s, LFT’s, glucose, ESR, CRP, May need other cultures e.g.- throat swabs, stool culture
20 - Contrast-enhanced CT/MRI scans: rule out space-occupying lesions, strokes. Identify raised intracranial pressure (a contra-indication for an LP).
MRI can show oedematous changes seen in encephalitis. - Electroencephalogram (EEG) – diffuse abnormal slow wave changes
Mx of encephalitis
- If viral - Urgent antiviral treatment (acyclovir 1st line- given high dose
IV usually for 14 days). Untreated mortality 70%, therefore
sometimes started empirically. - Supportive treatment +/- anti-seizure medications
- If meningitis is suspected- emergency IM benzylpenicillin.
