Multiple Sclerosis Flashcards
Multiple sclerosis presentation
This 30‐year‐old woman complains of double vision and incoordination with previous episodes of weakness. Please perform a neurological examination.
Clinical signs of Multiple Sclerosis
- Inspection: ataxic handshake and wheelchair
- Cranial nerves: internuclear ophthalmoplegia (frequently bilateral in MS), optic atrophy, reduced visual acuity, and any other cranial nerve palsy
- Peripheral nervous system: Upper‐motor neurone spasticity, weakness, brisk reflexes and altered sensation
- Cerebellar: ‘DANISH’ (see cerebellar syndrome section)
Medial longitudinal fasciculus (MLF)
- Medial longitudinal fasciculus (MLF): is a pair of tracts that allows for crosstalk between CN VI and CN III nuclei.
- Coordinates both eyes to move in same horizontal direction.
- Highly myelinated (must communicate quickly so eyes move at same time).
- Lesions may be unilateral or bilateral (latter classically seen in multiple sclerosis).
Internuclear ophthalmoplegia
- Internuclear ophthalmoplegia (INO) = Lesion in MLF, a conjugate horizontal gaze palsy.
- Lack of communication such that when CN VI nucleus activates ipsilateral lateral rectus, contralateral CN III nucleus does not stimulate medial rectus to fire.
- Abducting eye gets nystagmus (CN VI overfires to stimulate CN III).
- Convergence normal.
- When looking left, the left nucleus of CN VI fires, which contracts the left lateral rectus and stimulates the contralateral (right) nucleus of CN III via the right MLF to contract the right medial rectus.
- Directional term (e.g., right INO, left INO) refers to which eye is paralyzed. so the other eye will have nystagmus
Diagnostic criteria of Multiple Sclerosis
Central nervous system demyelination (plaques) causing neurological impairment that is disseminated in both time and space.
Cause of Multiple Sclerosis
Unknown, but both genetic – (HLA‐DR2, interleukin‐2 and ‐7 receptors) and environmental factors (increasing incidence with increasing latitude, association with Epstein–Barr virus infection) appear to play a role.
Investigation of Multiple Sclerosis
Clinical diagnosis plus
1. CSF: oligoclonal IgG bands
2. MRI: periventricular white matter plaques
3. Visual evoked potentials (VEPs): delayed velocity but normal amplitude (evidence of previous optic neuritis)
Other clinical features of Multiple Sclerosis
- Higher mental function: depression, occasionally euphoria
-
Autonomic: urinary retention/incontinence, impotence and bowel problems
==> Uthoff’s phenomenon: worsening of symptoms after a hot bath or exercise
==> Lhermitte’s sign: lightening pains down the spine on neck flexion due to cervical cord plaques
Treatment of Multiple Sclerosis
1. Multidisciplinary approach
2. Disease modifying treatments
3. Symptomatic treatments
Multidisciplinary approach in Multiple Sclerosis
- Specialist nurse,
- physiotherapist,
- occupational therapist,
- social worker and
- physician.
Disease modifying treatments for Multiple Sclerosis
- Interferon‐beta and Glatiramer reduce relapse rate but don’t affect progression.
-
Monoclonal antibody therapy potentially offers greater benefits; reducing disease progression and accumulated disability, e.g.
===> Alemtuzumab (anti‐CD52) – lymphocyte depletion,
===> Natalizumab (anti‐α4 integrin) – blocks T‐cell trafficking.
»» Toxicity may limit their use.
Symptomatic treatments for Multiple Sclerosis
- Methyl‐prednisolone during the acute phase may shorten the duration of the ‘attack’ but does not affect the prognosis.
- Anti‐spasmodics, e.g. Baclofen.
- Carbamazepine (for neuropathic pain).
- Laxatives for bowel disturbance.
- Intermittent catheterization/oxybutynin for bladder disturbance.
Prognosis of Multiple Sclerosis
Variable: The majority will remain ambulant at 10 years.
Multiple Sclerosis and pregnancy
- Reduced relapse rate during pregnancy
- Increased risk of relapse in postpartum period
- Safe for foetus (possibly reduced birth weight)
Impairment, disability and handicap in Multiple Sclerosis
- Arm paralysis is the impairment
- Inability to write is the disability
- Subsequent inability to work as an accountant is the handicap
» Occupational therapy aims to help minimize the disability and abolish the handicap of arm paresis.