Movement disorders are neurological conditions characterized by abnormality of the movements and gait.
Movements that appear relatively simple, such as picking up a bit of paper from the floor, are actually quite complex. They involve numerous instantaneous two-way signals from and to the brain and the motor organ. These are responsible for maintaining balance and producing a smooth, rapid and fluent movement which succeeds in performing the desired action. Thus problems in any part of this complex pathway can affect normal movements.
Characteristic Symptoms of Movement Disorders
Movement disorders are usually characterized by excessive spontaneous movements, abnormal involuntary movements, or by the paucity/ absence of movements, associated with rigidity and spasticity of muscles. The abnormal movements may be rhythmic, irregular, sustained or jerky.
They may lead to severe disability and difficulty in leading a normal life. These conditions produce a huge impact on society at large, as there is little hope of gainful employment. Indeed, many such patients may need constant care and supervision for day to day activities, including personal hygiene.
Most movement disorders begin slowly.
In most cases, a co-worker or spouse may notice the problem before the patient realizes it. There may be initial weakness and stiffness of the muscles, and there is usually an onset of involuntary movements.
These include twitches, tics, flapping or writhing movements of the arms and/or head and abnormal sounds or grunts.
The symptoms may persist throughout the day, or may appear only when the sufferer tries to perform a voluntary muscle task .
What Changes in Muscle Tone May be Expected?
The muscle tone may be increased or decreased, depending on the specific condition. Muscle tone refers to the resting activity of the muscles that prevents the limbs and torso from sagging and holds up the body even at rest.
With movement disorders such as dystonia, characterized by involuntary contractions over a period of time, the muscle tone is increased due to spasm (persistent contraction). Writhing, twisting or repetitive abnormal movements of any part of the body are common. Dystonia may be generalized or focal.
Types of Muscle Disorder Symptoms
There is a range of movement disorders. The symptoms and signs of these disorders vary with the types.
Tremors are the most common symptom of movement disorders. They appear in the head and face, especially the chin, or as a tremor of the voice or of the arms and legs. Tremors may occur at rest or may occur during attempts to perform a task. Essential tremor is the most frequently seen of these conditions.
Increased muscle tone may make it difficult for the physician to maneuver the limbs.
Cogwheel rigidity is seen in patients with Parkinson’s disease. This imparts a typical ratchet-like feel when the limb is moved passively.
Pain and spasm
Increased muscle tone may also be accompanied by pain and spasm of the muscles. This is also seen in the dystonias.
This term refers to the contraction of the eyelid muscles with the closure of one or both eyes. This is a type of focal dystonia.
This is a focal dystonia with intermittent spasms of the neck muscles causing different contortions of the neck.
Dyskinesia is characterized by a series of abnormal movements. Tics and tremors refer to rhythmic or pendulous movements of the arms and legs.
In tics there may be repeated movements such as twitches of the facial muscles, shrugging, grimacing, grunting or sighing.
Patients with dyskinesia may have hypokinesia (few movements), bradykinesia (slow movements) or akinesia (complete lack of movements).
Other types of dyskinesia include chorea (rapid jerky movements of the limbs), athetosis (slow writhing movements) or myoclonus (rapid, purposeless movements of the limbs that appear suddenly and disappear on their own) singly or in combination.
Patients report that they feel an involuntary “pulling” or “twisting” of the muscles before the movement appears.
Asterixis is another symptom characterized by a sudden loss of tone while attempting to maintain a limb in a certain position.
A typical feature is a flapping movement of the hands when the patient holds out the upper arm.
Symptoms Affecting Posture and Balance
Propulsion and retropulsion are symptoms affecting posture and balance. The typical features include stooping, being pulled to one side while walking, taking very short steps and the occurrence of easy falls while walking. These are seen in patients with Parkinson’s disease.
Ataxia causes imbalance and difficulties in gait and walking. This may manifest as clumsiness or lack of balance, or uncoordinated movements, or a tremor. Movements are jerky, and falls are more frequent.
Dysphonia refers to disorder of the voice caused by abnormality in the contraction of the muscles responsible for voice production.
At some times the patient may not be able to make any sound at all; at other times the voice is quivery, strained, hoarse or jerky.
Functional Movement Disorders
These conditions are not caused by any neurological disorder but their symptoms resemble those of a movement disorder.
Common Movement Disorders
Restless Leg Syndrome
Restless leg syndrome is characterized by sensations such as creeping, tingling or feeling of bugs over the legs (or sometimes the arms) especially at bedtime or when at rest. The feeling is relieved temporarily by movement of the limbs.
Other problems include disrupted sleep, insomnia and daytime fatigue.
This is genetic in origin and due to neurological deterioration, associated with chorea, loss of cognition and psychiatric symptoms, over the course of time.
Wilson’s disease manifests with symptoms of liver disease like jaundice in addition to be psychiatric and behavioral disturbances. These may include loss of concentration, cognitive decline, and depression. The diagnostic KF rings are seen in the eyes on examination. Rarely, seizures may occur.
Parkinson’s Disease and Parkinsonism
Parkinson’s disease is characterized by tremor at rest, rigidity and bradykinesia. There is diminished postural stability with frequent falls and a “shuffling gait”. There is diminished arm swing while walking.
Festination while walking refers to the posture adopted during walking, with the patient leaning forward and walking with fast, shortened steps. This can result in an involuntary forward acceleration.
Sometimes the patient may just “freeze” during a movement. There may be micrographia or progressive shortening of the letters written by the patient.
Several other symptoms are commonly seen including anxiety, depression and psychosis, heat/cold intolerance and sensory disturbances.