Symptom Finder - Tremor and Involuntary Movements
TREMOR AND OTHER INVOLUNTARY MOVEMENTS
Anatomy can assist one greatly in formulating a differential diagnosis of tremor of hepatic coma, Wilson disease, and alcoholism. The thyroid brings to mind the tremor of Graves disease. The kidneys signify the tremor of uremia and electrolyte disturbances. The heart suggests the choreiform movements of rheumatic fever (Sydenham chorea).
Finally, the CNS indicates a host of other causes that can be further differentiated by considering the tracts and nuclei of the brain. The substantia nigra and globus pallidus are the sites of Parkinson disease and other related diseases, especially chlorpromazine toxicity. The putamen is the site of gross cavitation and atrophy in Wilson disease. The red nucleus may be involved in the syndrome of Benedikt, a vascular occlusion of a branch of the basilar artery. The thalamic syndrome produces a unilateral tremor in the extremities and is caused by an occlusion of the thalamogeniculate artery.
Manganese, carbon monoxide poisoning, cerebral palsy, and general paresis all affect the brain and basal ganglia leading not only to a tremor but also to an organic brain syndrome in many cases. Huntington chorea produces bizarre choreiform movements; it can be recalled by its association primarily with atrophy of the caudate nucleus. Intention tremor is associated primarily with cerebellar disease. The tremor of cerebellar ataxia, olivopontocerebellar atrophy, multiple sclerosis, phenytoin (Dilantin) toxicity, and cerebellar neoplasms can be recalled in this fashion.
Considering the entire brain and brainstem will bring to mind viral encephalitis and postinfectious encephalitis. If one includes the spinal cord and peripheral nerves, Jakob–Creutzfeldt disease will be recalled. Other rare causes of tremor can be recalled by visualizing the tracts or nuclei of the brain that are most significantly involved.
A second method to recall quickly the causes of tremor is to apply the mnemonic VINDICATE.
V—Vascular disorders suggest thalamic syndrome and arteriosclerosis.
I—Inflammatory disorders signify encephalitides.
N—Neoplasms signify neoplasms of the cerebellum and brainstem.
D—Degenerative disorders bring to mind Parkinson disease, Wilson disease, Friedreich ataxia, and a host of other CNS disorders.
I—Intoxication recalls alcoholism; manganese, phenytoin (Dilantin), carbon monoxide, and lead toxicity; and hepatic and renal coma with tremors.
C—Congenital disorders suggest dystonia musculorum deformans and cerebral palsy. Familial tremor should be recalled here.
A—Autoimmune disorders suggest Sydenham chorea.
T—Trauma suggests the tremor in posttraumatic and postconcussion syndrome and in posttraumatic necrosis.
E—Endocrine disorders bring to mind hyperthyroidism.
Approach to the Diagnosis
The workup of tremor and other involuntary movements involves most of all a good history. A family history may identify familial tremor. Look for exposure to lead, manganese, and various drugs. The neurologic examination is important as it will determine the type of tremor. Rapid fine tremors (8 to 20 per second) are suggestive of hyperthyroidism and
emotional disorders. Coarser tremors at rest suggest Parkinsonism, whereas a flapping tremor of 4 to 8 per second suggests Wilson disease.
The association of other neurologic signs helps to pin down the diagnosis. Spasms of pain suggest a thalamic syndrome, ataxia suggests Friedreich ataxia, and loss of memory suggests manganese toxicity. Laboratory tests will be useful in selected cases. Blood lead, manganese, copper, and ceruloplasmin levels may be necessary. A triiodothyronine (T3), thyroxine (T4), and free T4 index will confirm the diagnosis of Graves disease.
Other Useful Tests
1. Drug screen (alcohol or drug abuse)
2. Chemistry panel (hypocalcemia, uremia, other electrolyte disorders)
3. EMG (timing of tremor)
4. MRI of the brain (multiple sclerosis, Wilson disease, cerebellar
tumor, etc.)
5. Neurology consult
6. Therapeutic trial of β-blockers (familial tremor)
7. Genetic testing (Huntington chorea, Lesch–Nyhan syndrome)
Anatomy can assist one greatly in formulating a differential diagnosis of tremor of hepatic coma, Wilson disease, and alcoholism. The thyroid brings to mind the tremor of Graves disease. The kidneys signify the tremor of uremia and electrolyte disturbances. The heart suggests the choreiform movements of rheumatic fever (Sydenham chorea).
Finally, the CNS indicates a host of other causes that can be further differentiated by considering the tracts and nuclei of the brain. The substantia nigra and globus pallidus are the sites of Parkinson disease and other related diseases, especially chlorpromazine toxicity. The putamen is the site of gross cavitation and atrophy in Wilson disease. The red nucleus may be involved in the syndrome of Benedikt, a vascular occlusion of a branch of the basilar artery. The thalamic syndrome produces a unilateral tremor in the extremities and is caused by an occlusion of the thalamogeniculate artery.
Manganese, carbon monoxide poisoning, cerebral palsy, and general paresis all affect the brain and basal ganglia leading not only to a tremor but also to an organic brain syndrome in many cases. Huntington chorea produces bizarre choreiform movements; it can be recalled by its association primarily with atrophy of the caudate nucleus. Intention tremor is associated primarily with cerebellar disease. The tremor of cerebellar ataxia, olivopontocerebellar atrophy, multiple sclerosis, phenytoin (Dilantin) toxicity, and cerebellar neoplasms can be recalled in this fashion.
Considering the entire brain and brainstem will bring to mind viral encephalitis and postinfectious encephalitis. If one includes the spinal cord and peripheral nerves, Jakob–Creutzfeldt disease will be recalled. Other rare causes of tremor can be recalled by visualizing the tracts or nuclei of the brain that are most significantly involved.
A second method to recall quickly the causes of tremor is to apply the mnemonic VINDICATE.
V—Vascular disorders suggest thalamic syndrome and arteriosclerosis.
I—Inflammatory disorders signify encephalitides.
N—Neoplasms signify neoplasms of the cerebellum and brainstem.
D—Degenerative disorders bring to mind Parkinson disease, Wilson disease, Friedreich ataxia, and a host of other CNS disorders.
I—Intoxication recalls alcoholism; manganese, phenytoin (Dilantin), carbon monoxide, and lead toxicity; and hepatic and renal coma with tremors.
C—Congenital disorders suggest dystonia musculorum deformans and cerebral palsy. Familial tremor should be recalled here.
A—Autoimmune disorders suggest Sydenham chorea.
T—Trauma suggests the tremor in posttraumatic and postconcussion syndrome and in posttraumatic necrosis.
E—Endocrine disorders bring to mind hyperthyroidism.
Approach to the Diagnosis
The workup of tremor and other involuntary movements involves most of all a good history. A family history may identify familial tremor. Look for exposure to lead, manganese, and various drugs. The neurologic examination is important as it will determine the type of tremor. Rapid fine tremors (8 to 20 per second) are suggestive of hyperthyroidism and
emotional disorders. Coarser tremors at rest suggest Parkinsonism, whereas a flapping tremor of 4 to 8 per second suggests Wilson disease.
The association of other neurologic signs helps to pin down the diagnosis. Spasms of pain suggest a thalamic syndrome, ataxia suggests Friedreich ataxia, and loss of memory suggests manganese toxicity. Laboratory tests will be useful in selected cases. Blood lead, manganese, copper, and ceruloplasmin levels may be necessary. A triiodothyronine (T3), thyroxine (T4), and free T4 index will confirm the diagnosis of Graves disease.
Other Useful Tests
1. Drug screen (alcohol or drug abuse)
2. Chemistry panel (hypocalcemia, uremia, other electrolyte disorders)
3. EMG (timing of tremor)
4. MRI of the brain (multiple sclerosis, Wilson disease, cerebellar
tumor, etc.)
5. Neurology consult
6. Therapeutic trial of β-blockers (familial tremor)
7. Genetic testing (Huntington chorea, Lesch–Nyhan syndrome)