Definition and types
Multiple Sclerosis is a chronic, inflammatory demyelinating disease of the central nervous system. The demyelination occurs in the periventricular white matter, optic nerve, brainstem, cerebellum, and/or spinal cord.
There are three types based on the clinical course:
- Relapsing-remitting MS (RR-MS)
- Primary progressive MS (PP-MS)
- Secondary progressive MS (SP-MS)
Relapsing-remitting is the most common subtype, in which the patient has relapses with symptoms of MS followed by remission of the symptoms. The symptoms develop over hours or days and then remit over the next weeks. There is no progression of the symptoms in the periods between disease relapses. If the patient has only had one attack of MS-like symptoms (one relapse), they are said to have a “clinically isolated syndrome” (CIS).
Primary progressive type is the worst subtype, in which the patient has no remission of the symptoms but rather continuous progression and worsening.
Some cases or relapsing-remitting type may progress into secondary progressive type, where the patient stops having remissions and instead have continuous progression.
The patient may present with symptoms of a single lesion or with symptoms of lesions in multiple of the predilected sites in the CNS.
The first symptom is usually those of optic or retrobulbar neuritis, which appears as unilaterally impaired vision and retrobulbar pain.
Lesions in the spinal cord can manifest as weakness, spasticity, hyperreflexia, sensory loss, urinary incontinence. Lhermitte sign may be present, when the patient feels an electric shock down the spine when flexing the neck.
Lesions in the cerebellar involvement can manifest as cerebellar symptoms like dysarthria, ataxia, intention tremor and nystagmus.
Lesions in the brainstem can manifest as diplopia, vertigo, facial numbness, etc.
13A. Ischias syndrome and cervicobrachialgia (symptoms, warning signs)
14A. Motor neuron diseases