Neurology
Summary
Multiple sclerosis (MS) is a chronic, progressive inflammatory disease characterized by immune-mediated demyelination within the central nervous system (CNS). The most prevalent type of MS presents with a relapsing-remitting flare pattern, where episodes are punctuated by periods of partial or complete recovery, and each episode can manifest with different symptoms. Several risk factors contribute to the development of MS including a genetic predisposition, notably the association with HLA-DRB1, a family history of MS or other autoimmune diseases, a higher female prevalence (ratio of 3:2), and environmental factors such as higher latitudes leading to reduced sun exposure and potential vitamin D deficiency. Additionally, there's an association between MS and the Epstein-Barr virus (EBV).
Clinically, MS showcases a myriad of symptoms. Lhermitte sign is described as an electric shock sensation radiating down the back upon neck flexion. Patients might also experience varied sensory disturbances such as paresthesias, numbness, and itching, especially in the face and limbs. Motor deficits include poor coordination, gait imbalance, and signs of upper motor neuron involvement like extremity weakness, spasticity, and hyperreflexia. Unique ocular manifestations include optic neuritis, characterized by monocular vision loss and painful eye movement, and bilateral internuclear ophthalmoplegia (INO), which results from demyelination of the medial longitudinal fasciculus. Other notable features in MS include nystagmus, trigeminal neuralgia due to demyelination of the trigeminal nerve, urinary incontinence (which can be an early prognostic sign), and the classic Charcot neuro triad indicating cerebellar involvement, comprised of scanning speech, nystagmus, and intention tremor. The Uhthoff phenomenon describes the exacerbation of symptoms with elevated temperatures, such as during hot showers or fevers.
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FAQs
Multiple Sclerosis (MS) is a chronic, progressive, inflammatory immune-mediated demyelinating disease of the Central Nervous System (CNS). MS can present a variety of symptoms, with the most common being the relapsing-remitting flare pattern. This means there are periods of partial or full recovery in between episodes, which can involve different symptoms each time such as sensory symptoms, poor coordination, as well as upper motor neuron symptoms.
Factors such as genetic predisposition, notably the HLA-DRB1 association, and having a family history of MS or other autoimmune diseases can increase an individuals chances of developing MS. It has also been observed that there is female prevalence of MS with a ratio of 3:2. MS has a higher incidence in locations further away from the equator which is attributed to less sun exposure and possible vitamin D deficiency. The Epstein-Barr Virus (EBV) has also been associated with MS.
Several distinct symptoms and signs can occur in MS. These include Lhermitte sign which is an electrical shocking sensation down the back when the neck is flexed, varying sensory symptoms such as paresthesias, numbness, itching or burning sensation, poor coordination, urinary incontinence, and the presence of Uhthoff phenomenon where symptoms worsen with temperature. Optic neuritis can result in monocular vision loss, painful eye movement, washed out color vision, and the peculiar Marcus-Gunn pupil. Neurologic symptoms can include impaired lateral conjugate gaze, a characteristic form of nystagmus, and trigeminal neuralgia due to demyelination of the trigeminal nerve axon. Finally, a classic triad of symptoms indicating cerebellar involvement known as Charcot neuro triad can also appear and consists of scanning/staccato speech, nystagmus, and intention tremor.
Multiple Sclerosis shows a predilection towards certain demographics. Women have a higher predisposition to MS than men, with a female to male prevalence ratio of 3:2. It also seems to have a higher incidence the further away from the equator in both hemispheres presumably due to less sun exposure, and possible Vitamin D deficiency as a contributing factor. Additionally, those with a family history of MS or other autoimmune diseases have a higher chance of developing MS.
The most common type of MS is known as the "relapsing remitting" type. This subtype of the disease is characterized by periods of acute symptoms, or "flares," with partial or complete symptom recovery in between these episodes. The symptoms experienced during a flare can vary greatly from person to person and even from flare to flare within the same individual. Apart from this, certain signs such as Lhermitte sign, specific visual symptoms due to optic neuritis, and a particular pattern of movement issues like poor coordination and intention tremor can appear.
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