Family Practice Issues in Neurology

Fall 1999
Volume 10, Number 2

 Next Article  

The complex diagnostic process for movement disorders is essentially one of phenomenology first, neurologic examination second, and any supportive laboratory testing last. In this brief article, an approach to diagnosis and treatment is outlined for the primary care physician. More detailed information is available from the recommended references and resource materials at the end of the article.

General Approach. Perhaps one of the greatest challenges for the primary care physician is the recognition of uncommon conditions. Movement disorders are usually diagnosed by “pattern recognition.” The complex diagnostic process is essentially one of phenomenology first, neurologic examination second, and any supportive laboratory testing last. In this brief article, an approach to diagnosis and treatment is outlined for the primary care physician. More detailed information is available from the recommended references and resource materials at the end of the article.

Hypokinetic Disorders. Slowness of normal movement (bradykinesia), lack of movement (akinesia), and difficulty initiating movement are the hallmarks of hypokinetic disorders. While most physicians recognize classic Parkinson’s Disease (PD), the many other forms of parkinsonism can be difficult to diagnose and treat. Table 1 lists the differential diagnosis for parkinsonism. The most helpful finding on examination of a parkinsonian patient is the presence or absence of resting tremor in one limb. If such a tremor is present, idiopathic PD is the likely diagnosis. If not, other diagnoses and perhaps additional testing or referral to a specialist must be considered.

At the present time, a cure for PD is not yet available, although progress is occurring at a rapid pace. Until a cure is proven, the treatment of PD symptoms is not mandatory unless the symptoms are disabling. The patient’s age, occupation, location of symptoms, etc, must be considered before beginning treatment. It is also important to note that the treatment strategy differs for different age groups. Emerging data suggests that younger onset PD patients (ie, age 20 to 60 years) may do better over time using dopamine agonist monotherapy as initial treatment. The longer half-life and lack of pulsatile dopamine stimulation from the agonist may reduce the emergence of motor fluctuations and dyskinesia. Table 2 lists the 4 currently available dopamine agonists. In the older patient, simple treatment with levodopa (Sinemet or Sinemet CR) at the lowest effective dose is sufficient to control symptoms. Levodopa is also the most efficacious in patients with confounding medical conditions, such as orthostatic hypotension or congestive heart failure.

Patients with atypical parkinsonism or secondary parkinsonism (ie, due to stroke or toxin exposure) do not typically respond well to standard anti-parkinson medications. The most common of those disorders seen by clinicians include multi-infarct parkinsonism, Progressive Supranuclear Palsy, and Diffuse Lewy Body Disease. The latter appears as concomitant dementia, affective disturbance, and parkinsonism. Such patients may have REM Behavior Disorder (see CNI Review, Spring 1999). When exposed to neuroleptic medications they may become profoundly rigid and bradykinetic.

When patients begin to have complications from advancing PD, referral to a PD specialist is generally warranted. There are an increasing number of pharmacological and surgical strategies available even for complex patients (see CNI Review Winter 1998-1999, Movement Disorders).

Hyperkinetic Conditions. Tics. Tics are fragments of normal movements or sounds that occur inappropriately and out of context. They are often suppressible for brief periods. There is usually an urge, which precedes the tic, and relief after it occurs. In the most fully developed form, Tourette’s Syndrome (TS) is defined as the presence of movement and noise tics for greater than one year beginning before the age of 21. Transient or less complex tic disorders are common. Generally not considered an illness, tic disorders appear to have a genetic basis but may have some basis in the immune system response to streptococcal infection. Table 3 lists several conditions associated with tics. Treatment is not mandatory unless symptoms are disabling. Pharmacological and non-pharmacological interventions must be tailored to the specific problems requiring treatment.

Chorea. Chorea is defined as brief small movements that often begin to interfere with purposeful actions. When mixed with more sustained, writhing movements the term choreoathetosis is appropriate. Table 4 lists some of the more common causes of chorea. Given the serious and complex nature of most conditions associated with chorea, referral to a neurologist is warranted.

Myoclonus. Myoclonus is the fastest involuntary movement. Typically less than 100 msec in duration, myoclonus arises from loss of inhibitory neuronal control at cortical, sub-cortical, or spinal cord levels. Differential diagnosis is quite broad and specialized diagnostic evaluation is recommended. The most common cause is cerebral anoxia following cardiac arrest. Treatment may be successful with suppressing medications, such as clonazepam or valproate.

Dystonia. Involuntary contraction of agonist and antagonist muscles may result in postural deformity. Typically worse with action, dystonia may effect focal regions (eg, the neck) or the whole body. Spasmodic Torticollis or cervical dystonia is the most common focal dystonia and is usually a disorder of adults. Quite variable in appearance, torticollis should be referred to a specialist for diagnosis and treatment. The focal dystonias are most often treated with injections of botulinum toxin into the over-active muscles. The generalized dystonias typically begin in childhood and have a genetic basis in most cases. Genetic testing and counseling should accompany treatment by an experienced neurologist.

Tremor. Tremor is defined as rhythmic oscillation of a body part. There are more than 20 kinds of tremor. The most useful distinction is between resting and action tremors. Rest tremor occurs when a body part, such as the hand, is not in use. The typical rest tremor has a frequency of 3 to 6 cps and will disappear with any movement, even a simple change in position. When present, particularly if unilateral, this finding almost always represents PD. The rare conditions other than PD are diagnosed by the findings of other neurologic signs and symptoms.

Action tremors are more common and fall into 3 or 4 categories as listed in Table 5. Diagnosis depends on the presence or absence of other risk factors, family history, response to alcohol, and neurologic examination. Treatment is based on diagnosis. The most common familial tremor is called Essential Tremor (ET). Essential Tremor usually begins in young adult or mid-life and effects hands, head, and voice. Treatment ranges from low-dose beta-blockers (either daily or prn), primadone, or Deep Brain Stimulation (DBS). The latter is extremely effective but reserved for patients with disabling tremor whom have failed standard medical therapy.

Physiologic tremor is fairly common. It is a fast frequency (8 to 12 cps), of low amplitude and brought on by exertion, fatigue, and sympathomimetic agents. Treatment is usually not required. Drug-induced tremor may be caused by a wide range of prescription, over-the-counter and illicit drugs. Tremor due to hyperthyroidism responds nicely to treatment of the under-lying condition.

Ataxia. Disorders of gait are quite complex. Ataxia refers to the wide based unsteady gait and coordination difficulty usually associated with cerebellar dysfunction. Table 6 lists the most common causes of ataxia. It is important to recognize that some ataxic gaits are due to proprioceptive sensory deficits. These may occur with cervical stenosis and compression of the posterior columns of the spinal cord, vitamin B12 deficiency, neurosyphillis, malabsorption syndromes, and inherited conditions. Modern neuroimaging with magnetic resonance imaging (MRI) and genetic testing have revolutionized our ability to diagnose ataxia. Treatment of reversible conditions, such as B12 deficiency, is obviously the primary goal. Symptom management with physical therapy and oral medications may be beneficial. Genetic counseling is recommended for appropriate cases.

Focal Muscle Spasm. Occasionally, focal muscle hypertrophy and spasm is not due to dystonia or spasticity. Rare cases due to isolated motor nerve injury may be quite perplexing. Accurate history taking and electromyography usually reveal the diagnosis. Treatment is most successful with precise injections of botulinum toxin (Botox®) into the effected muscle.

Psychogenic Movement Disorders. These are the most challenging of all movement disorders. Rigorous criteria have been proposed for the diagnosis of a psychogenic disorder. It is not simply a diagnosis of exclusion. The most striking feature of psychogenic movements is that they are inconsistent or incongruent with classical disorders. Often, other findings support the diagnosis, such as false weakness or false sensory findings. Multiple somatizations or other psychiatric disturbances may be present. The psychogenic movement disorder may disappear with distraction. When unsure, referral to a movement disorder specialist is strongly encouraged. Although treatment is difficult, a good outcome may be possible when a team approach includes psychiatry or psychology expertise.

Conclusion. The primary care physician plays a crucial role in the process of identification and management of movement disorders. Awareness of hypokinetic and hyperkinetic conditions permits early identification of reversible conditions. For most patients optimal long-term management occurs with a partnership between primary care physicians and movement disorders specialists.

Resources. Several well-written resources are available to the clinician. In addition to the textbooks listed, interactive CD-ROM Neurology encyclopedias with video and other graphic material can be of great value. One such guide is called NeuroBase available by subscription. Further information can be found at www.neurobase.com.

Address comments and questions to:

Christopher F. O’Brien, MD
CNI Movement Disorders Center
701 East Hampden Avenue, Suite 530
Englewood, CO 80113

 Next Article