Patients With Abnormal Movements

Overview

Psychiatrists encounter patients with abnormal movements in various clinical settings. Recognizing and correctly labeling motor phenomena in each setting helps to create a differential diagnosis that serves as the basis for optimal treatment, since abnormal movements can be the first indication of an unsuspected medical or neurologic disorder in a psychiatric patient treated for psychiatric symptoms. A solid understanding of prototypical movement disorders (e.g., Huntington's disease, Parkinson's disease) and of tremors will help psychiatrists to correctly categorize abnormal movements. All movement disorders, primary or drug-induced, contribute to morbidity (with loss of independence) and mortality (e.g., secondary to falls or choking). Many are stigmatizing, as abnormal movements are immediately obvious to others.

Movement disorders caused by basal ganglia damage all create trouble starting or stopping movements. They differ from cerebellar disorders, which affect movement targeting, and from stroke-related weakness. Neuroleptic malignant syndrome and catatonia are discussed in Chapters 12 and 23 , respectively. Real patients and videos are excellent ways to learn to recognize abnormal movements. A word of caution: many of the free videos on the Internet show patients with functional movement disorders who have made videos of themselves and do not depict classic movement disorders; therefore, one should select reputable sources, such as a video atlas.

Patient History and Physical Examination

A movement disorder is a clinical diagnosis, based on history and physical examination; laboratory tests and brain imaging usually do not facilitate making the diagnosis. A family history can be informative for hereditary movement disorders. One should ask carefully about present and past medications as well as substance use, as these are the most common causes of abnormal movements.

The examination begins with unobtrusive observation, when meeting the patient in the waiting area or approaching the bedside. One should determine if the movements exist when unobserved, and if the patient shuffles or writhes when walking. A patient who lies stiffly in bed might be parkinsonian, or catatonic. The neurologic examination is focused on establishing deficits beyond their relationship to the motor strip and the basal ganglia, and includes cortical functioning and cerebellar function as well as on eliciting other motor signs. Muscle tone should be determined (e.g. rigid, spastic, or hypotonic). If you suspect catatonia, you should perform an exam for other signs of catatonia. Some patients cannot relax while their limb is being examined for muscle tone, and seem to (voluntarily) resist each passive movement. This is called gegenhalten or paratonia.

Table 21-1 summarizes common movement symptoms. Overall, it is helpful to determine if your patient moves too much (hyperkinetic) or too little (hypokinetic), or if there are rhythmic tremors or non-rhythmic twitches. Myoclonus or asterixis can appear somewhat rhythmic on first glance, so one must observe carefully. Asterixis can suggest a serious metabolic disturbance, whereas myoclonus is non-specific and may be benign. Other phenomena that mimic tremor include focal seizures and cerebellar dysmetria. Some movements defy easy categorization but should be considered in psychiatric patients (e.g., catatonic symptoms, stereotypies, mannerisms).

When examining a patient with a tremor the main question is whether the tremor occurs mainly at rest (resting tremor) or during action (action tremor). Postural tremors can occur with either action or rest and are not themselves diagnostic. Writing or drawing will reliably evoke an action tremor in that hand, whereas rest tremors can intensify with movement of the opposite hand. The phenomenologic description of the tremor is followed by an examination of other neurologic signs or symptoms to help refine the diagnostic possibilities. This matters, since treatment depends on the tremor's etiology, although the treatment of some tremors can be non-specific and based on its severity and the patient's tolerance of it.

Table 21-2 summarizes gait disorders. Observing a patient's gait and understanding the etiology of a gait disturbance are particularly important during a patient visit. Gait disturbances not only limit a patient's independence but can lead to dangerous falls (especially in the elderly). Hypokinetic movement disorders, including parkinsonism associated with use of antipsychotics, lead to falls because patients react too slowly when they stumble. Ataxia or hyperkinetic movement disorders lead to fewer falls. A potentially reversible cause of a gait disturbance is normal-pressure hydrocephalus (NPH) that is manifest by a triad of (parkinsonian) gait, incontinence, and dementia (the latter being a late-stage manifestation). If diagnosed early, placement of a shunt can be curative.

One should also ask about swallowing difficulties, which can result in aspiration pneumonia.

Idiopathic Movement Disorders