The relative roles of grammatical processing and memory in the language comprehension difficulties of patients with Parkinson's disease (PD) were evaluated. Twenty PD patients who did not have dementia were exposed to a new verb in a naturalistic setting. After 10 min, the semantic and grammatical information that they learned about the new verb was probed. Significant impairments in recalling some aspect of the new verb were seen in 55% of PD patients. Most of these patients demonstrated a language-sensitive deficit in appreciating grammatical information represented in the new verb. A small number of PD patients responded randomly to probes of all information about the new word, which suggests a memory impairment. It is concluded that difficulty in appreciating grammatical information contributes to the language impairments of PD patients.Patients with Parkinson's disease (PD) have been shown to have sentence comprehension difficulties. For example, Natsopoulos et al. (1991) found that PD patients are significantly impaired at pointing to a picture when instructed to do so with a grammatically complex sentence. Lieberman and colleagues (Lieberman, Friedman, & Feldman, 1990;Lieberman et al., 1992) demonstrated significant impairments in some PD patients on a test of grammatical comprehension that also involved sentence-picture matching. Grossman and colleagues (Grossman et al., 1991;Grossman, Carvell, Stern, Gollomp, & Hurtig, 1992) observed that 65% of nondemented PD patients were significantly compromised in their ability to answer simple questions about sentences that featured subordinate clauses. Moreover, this impairment appears to be selective for grammatical aspects of language. Grossman et al. (1991;Grossman, Carvell, Stern, Gollomp, & Hurtig, 1992) thus demonstrated that comprehension of sentences with subordinate phrases improved in PD patients when the sentences contained nonreversible nouns (e.g., "The worm that the eagle chased was fat."). Similarly, Grossman, Carvell, and Peltzer (1993) found that PD patients were impaired at pointing to a picture illustrating a mass or count type of material when grammat-

We evaluated the ability of nondemented patients with idiopathic Parkinson's disease (PD) to interpret various aspects of sentences and to perform learned limb and oral gestures. The patients were significantly compromised in their ability to answer simple questions about sentences such as "The eagle chased the hawk that was fast. Which bird was chased?" A discriminant analysis revealed that up to 73% of PD patients differ from control subjects in their ability to perform this task. Patients with PD were also significantly compromised in their gestural performance, and a discriminant analysis indicated that a praxis deficit may be evident in up to 64% of patients. We conclude that language and gestural processing impairments are frequent in patients with PD.

Sirs: Schwab et al. [11] first described the antiparkinsonian effects of amantadine (Symmetrel) after the fortuitous discovery that the rest tremor, rigidity and akinesia of Parkinson's disease (PD) were improved in patients taking amantadine as influenza A prophylaxis. There have been numerous subsequent reports of its efficacy, and most have found amantadine to be effective in over 50% of PD patients [2,5]. Amantadine has been effective in combination with carbidopa/ levodopa [5], in levodopa-resistant patients [4], and in drug-induced parkinsonism [9]. Side effects include leg oedema, livedo reticularis, psychosis and confusion, especially in patients with underlying cognitive disturbances. All resolve when the medication is discontinued [1]. Although a small percentage of patients will have sustained improvement (> 1 year) [5,12] most respond for only a few months or less [2,13].The most effective drug for symptomatic treatment of PD is carbidopa/ levodopa, but chronic treatment is usually complicated by adverse effects including response fluctuations ("wearing-off" and "on-off" reactions), dyskinesias, and dystonia [7,8]. These complications are often difficult to treat. Amantadine has demonstrated short-term efficacy in two studies of patients with advanced PD and motor fluctuations [3,13]. Although other authors have noted anecdotal evidence for this effect [6], these are the only published reports we could find. Our experience has shown that amantadine can also have a long-term, favourable effect on patients with advanced disease having fluctuations and dyskinesias.We have reviewed the charts of four advanced PD patients treated with amantadine, over a 2-year period. A 64-year-old man noticed left shoulder discomfort and left arm tremor at age 37 years, and had a good, immediate response to right thalamotomy at age 41. However, symptoms progressed and he started levodopa at age 43. He improved, but developed dyskinesias within the 1st week. Bromocriptine was added with good benefit for 6 years, before further fluctuations and dyskinesias supervened. He participated in trials of pergolide, lisuride and Sinemet CR, without improvement; then selegiline was added. While on 550 mg levodopa, 40 mg bromocriptine and 5 mg selegiline per day, he had disabling motor fluctuations with dyskinesias. The on:off ratio was 20:80. Selegiline was discontinued and amantadine, 100 mg 2 ×/day, was started. The on:off ratio changed to 50 : 50 within 2 weeks. Over the next month the dyskinesias decreased to about 15% of the "on" time, and his "off" time became less disabling. He has had sustained functional and objective improvement for more than 2 years.The second patient was a 64-yearold man who developed PD at age 50 years. Carbidopa/levodopa was begun at age 53 and he eventually developed motor fluctuations and dyskinesias 3-4 years later. Bromocriptine, then pergolide, was used in combination with carbidopa/levodopa with initial benefit, but eventually fluctuations and dyskinesias worsened. A drug holiday was of no benefit...

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Thirty years ago, Parkinson disease was described as a shortage of the neurotransmitter dopamine. Today, understanding of this disorder includes possible genetic influences, premorbid and nonmotor issues, and a variety of neurologic, cognitive, and psychiatric symptoms. Using a case study, this article presents the current science of Parkinson disease.