MOVEMENT DISORDER

Movement disorders are neurologic conditions that cause problems with movement, leading to Increased movement that can be voluntary (intentional) or involuntary (unintended) or Decreased or slow voluntary movement.

The most common disorder that decreases and/or slows movement is

Parkinson disease : Parkinson disease is a neurodegenerative disorder that mostly presents in later life with generalized slowing of movements (bradykinesia) and at least one other symptom of resting tremor or rigidity. Other associated features are a loss of smell, sleep dysfunction, mood disorders, excess salivation, constipation, and excessive periodic limb movements in sleep. Postural instability is usually seen late in the disease and can seriously impact the quality of life. Patients respond well to pharmacological treatment. Lifestyle modifications, regular exercise, and appropriate rehabilitation measures enhance the functional status of individuals with parkinsonism.

Disorders that increase movement include

Tremor: Tremor is the most common movement disorder. Tremor is defined as an involuntary, rhythmic, and oscillatory movement of a body part. It is caused by either alternating or synchronous contractions of antagonistic muscles. Essential tremor is the most common neurologic cause of postural or action tremor. An intention, rubral, cerebellar, or coarse tremor are high amplitude tremor which worsen before reaching the target.  Intention tremors can present with deficits in corticocerebellar tracts due to physiological or pathological disease.

Myoclonus: Myoclonus describes an involuntary and uncontrollable muscle contraction disorder consisting of sudden, brief, and lightning-like movements of a specific muscle, group of muscles, or even the entire body. Myoclonus can be a benign and temporary occurrence or a persistent and debilitating condition with a wide range of underlying etiologies, from genetic factors to neurological disorders, metabolic abnormalities, or medication side effects. Myoclonus may emerge from generalized, multifocal, focal, or segmental distributions. Organized approach to diagnosis and clinical decision-making can significantly impact their quality of life.

Dystonia: Dystonia is an involuntary contraction of agonist and antagonist muscles causing abnormal posturing, twisting, and repetitive movements that are initiated or worsened by attempted movement. Patient present with overextension or over-flexion of the hand, inversion of the foot, lateral flexion or retroflexion of the head, torsion of the spine with arching and twisting of the back, forceful closure of the eyes, or a fixed grimace. With appropriate management people with dystonia can live a relatively normal life.

• Chorea, Athetosis, Ballismus: a state of excessive, spontaneous movements, irregularly timed, non-repetitive, randomly distributed and abrupt in character. Chorea is usually accompanied by athetosis and ballism. Athetosis is a slower form of chorea. The slowed movements have a writhing or twisting motion. Ballism is a very severe form of chorea where there is a violent flinging of the extremities. Causes include
• Endocrine and metabolic: hypoglycaemia, hyperthyroidism, kernicterus, hypomagnesemia.
• Infectious: rheumatic fever, syphilis, subacute sclerosing panencephalitis, Lyme disease, toxoplasmosis, HIV, endocarditis
• Drugs: levodopa, oral contraceptive, neuroleptics, antihistamines, cocaine, amphetamine, tricyclic antidepressants.
• Toxins: CO poisoning, mercury, alcohol intoxication
• Neurologic: stroke, migraine
• Vascular: polycythaemia, Churg Strauss, SLE, Behcet, Multiple sclerosis
• Malignant: primary brain tumors and metastatic lesions

Tics: common neurodevelopmental disorder which starts in childhood. Patients present with multiple motor and vocal tics. tics have 3 components:

1. Premonitory urge
2. Physical expression of the tic
3. Sense of relief experienced afterward

Motor tics are sudden, rapid, recurrent, nonrhythmic stereotyped motor movements, generally preceded by an urge. They can affect any part of the body but are by far most common in the face, head, and neck region. Vocal tics include any tic that produces noise: sniffing, grunting, humming, clicking, yelling words repetitively. 

Restless leg syndrome: common chronic movement disorder in which patients have an irresistible urge to move their leg. The non-painful but strong perceived need to move their legs when their legs are at rest is relieved with leg motion. There is a diurnal pattern wherein symptoms worsen at night, and sleep disturbance is often a problem. Restless leg syndrome is underdiagnosed, and there is a significant delay in diagnosis.

Akathisia: Akathisia is a neuropsychiatric syndrome that can occur as an adverse effect of antipsychotic medications and manifests as psychomotor restlessness. It is inability to remain still. It may be associated with the use of antipsychotic medications.