The hallmark of multiple sclerosis is unpredictable periods of exacerbation, remission, and progression. Initial symptoms of MS may be brief and mild. The first serious attack usually lasts weeks or months and occurs between the ages of 20 and 40.
The most common early symptoms include sensory abnormalities (e.g., tingling, numbness, itching, tightness, burning, shooting pain in the back and limbs [Lhermitte's sign]) difficulty walking, eye pain, and vision loss.
Symptoms of the disease vary, depending on where the damage occurs, and range from minor physical annoyances to major disabilities. Common symptoms include the following:
- Balance and equilibrium abnormalities (e.g., dizziness, vertigo, uncoordinated movements, tremor)
- Bladder and bowel dysfunction (e.g., urgency, incontinence, nocturia, constipation)
- Behavioral changes (e.g., mood swings, depression)
- Cognitive dysfunction (e.g., impaired memory, reasoning, concentration)
- Facial numbness
- Motor abnormalities (e.g., muscle weakness, spasticity, spasm)
- Sexual dysfunction (e.g., erectile dysfunction, sexual inactivity)
- Vision abnormalities (e.g., eye pain, vision loss in one eye, double vision [diplopia], involuntary eye movement [nystagmus])
Muscle weakness can involve the extremities (arms and legs) on one side of the body (hemiparesis), both legs (paraparesis), or all four extremities (quadraparesis). Muscles in the affected area may tighten (spasticity) and contract spontaneously (spasm or clonus).
Many people with MS experience fatigue and need to rest and sleep during the day in order to continue their activities. The degree of fatigue may not be related to the severity of other symptoms.
An increase in body temperature (e.g., caused by hot weather, hot bath and showers, or fever) can worsen symptoms or produce new ones. This occurs because elevated body temperature slows nerve impulse conduction, especially in demyelinated nerves.