Stumbling down the block, I landed on my hip and began jerking my arm; the event stressed me out. I grabbed for my wallet but found my tremoring hand unable to seize it from the grasp of a robber who had witnessed my tangled mass of taut muscles in a grounded heap.
A walking disorder leading to a fall
An involuntary arm jerking
Tremor in a hand
Tightly stretched muscles
Multiple Sclerosis (MS) involves scenarios, often dramatic, always clinical.
Such is what Movement Disorders are all about…phenomena, clinical phenomena.
All Movement Disorders are fair game in MS. Rarely, fleeting tics of the face and neck or dance like chorea of the trunk or arms…More commonly, limb tremor with intention and ataxic gait manifested by poor coordination of the trunk and/or legs…
And Movement Disorders in MS can be worsened by fear and emotional turmoil. Such is the case for many Movement Disorders irrespective of the underlying disease. When muscles are taut, they have abnormally increased tone- i.e., pathological hypertonicity. In MS, this can be due to motor tract damage- part of a so called “upper motor neuron lesion” .This can lead to a scissoring gait seen in MS patients’ knees and thighs crossing in succession like the opening and closing of scissors.
Sometimes such spasticity can be complicated by something called dystonia where the problem is not only increased muscle tone but odd postures such as neck twisting to one side or the other. Dystonia can also exist alone as an isolated Movement Disorder in MS. One or more muscles or muscle groups can be involved in spasticity or dystonia.
Walking itself is a complex movement. So much can go wrong. So much had to be learned to master it in the first place. We take so much for granted Standing balance can be lost, step alignment can be impaired, sideways or back and forth rocking can impair the gait’s rhythm. Demyelination of tracts that are involved with muscle tone lead to the scissoring described above. Weakness of muscles can complicate all of the involuntary and voluntary defects in muscle movement, impairing gait even more.
As one of the Great Imitators, MS can confuse the patient and the treating physician. Lightening like movements (myoclonus) can interrupt a relative immobility. Is it MS? Is it another degenerative disorder?
Some movements are associated with seizures, which can infrequently occur in MS. Such is another cause that sometimes needs to be evaluated in patients with unexplained movements in the setting of demyelinating disease.
Absence of movement (akinesia, freezing), slow movement (bradykinesia), rest tremor, rigidity…all aspects of** Parkinson’s Disease** (PD), can also intrude into the array of abnormal movement in MS, not typically as an added disease such as PD, but as a problem within the MS spectrum of Movement Disorders.
Plaques in the cerebellum, brain stem, basal ganglia or in other regions of the brain under the cerebral cortex (subcortical regions) are culprits for MS Movement Disorders.
Movement Disorders in MS due to psychiatric manifestations, infection or medication also must be considered.
Most Movement Disorders in MS and in general disappear during sleep. One exception, sometimes associated with MS is Restless Leg Syndrome, and also Periodic Leg Movements. This condition can disrupt sleep due to the awakening effect of leg thrusts and lead to daytime fatigue.