Daniel H. Jacobs

Emotional facial imagery, perception, and expression in Parkinson's disease.

Patients with Parkinsons disease (PD) may be impaired at expressing emotional faces and perceiving emotional facial affect.We tested the hypothesis that patients with PD may be impaired at imaging emotional faces. We first compared 12 patients with PD and 30 control subjects on perceptual and imagery tasks. Patients were significantly impaired on a task of emotional facial imagery but not on a control task of object imagery. Patients were also impaired on a task of perceiving emotional faces. Subsequently, we found that PD patients were impaired relative to controls on making emotional faces. Performance on both the perceptual and motor tasks of facial expression significantly correlated with performance on the emotional facial imagery task. We suggest that the basal ganglia, together with the right hemisphere, are part of a neural network subserving emotional facial tasks. NEUROLOGY 1995;45: 1696-1702

Anosognosia for hemiplegia An electrophysiologic investigation of the feed‐forward hypothesis

The cause of anosognosia for hemiplegia (AHP) remains unclear. Weakness is detected when there is a mismatch between the expectancy of movement and the sensory perception of movement. The feed-forward hypothesis of AHP posits that there is a failure of detection because there is a loss of motor intention and expectancy of movement. We tested motor intention by measuring the activation of proximal muscles (pectoralis majoris) while subjects squeezed a dynamometer with each hand. We tested a group of normal controls, a group of patients with hemi-paresis, a patient with neglect, a patient with resolved AHP, and a patient with persistent AHP. The patient with AHP did not contract either of his pectoralis muscles when asked to squeeze with his contralesional, paretic hand, yet he contracted both of them when squeezing the dynamometer with his ipsilesional hand. Normal controls, hemiparetic controls, and the patient with hemispatial neglect contracted both pectorales when asked to squeeze with each hand. The pattern of activation seen in the patients with persistent AHP and resolved AHP demonstrates a loss of motor intention and lends support to the feed-forward hypothesis of AHP.

Right-left confusion in Gerstmann's syndrome: a model of body centered spatial orientation.

Gerstmanns syndrome encompasses the tetrad of finger agnosia, agraphia, acalculia and right-left confusion and is associated with lesions of the dominant angular gyrus. The localizing value of this syndrome has been questioned because multiple mechanisms can account for each of the components of the syndrome. We present the case of a man who developed Gerstmanns syndrome following a focal infarct of the left angular gyrus. The patients right-left confusion could not be accounted for by either an aphasia or a degraded body schema. A series of experiments that investigated the patients spatial mapping system by progressively restricting the degrees of freedom for spatial rotation revealed an isolated defect in deriving the relative position of an object along the horizontal axis. Defective horizontal mapping can account for the other components of Gerstmanns syndrome because they all share a common dependency on relative horizontal positioning.

Impaired perception of facial identity and facial affect in Huntington's disease

Article abstract—We tested five patients with Huntingtons disease on tasks of facial discrimination and facial affect discrimination and matching. Four patients were impaired on a task or tasks of face discrimination, and all patients were impaired on at least one task of facial affect discrimination. We suggest that these findings reflect the role of the basal ganglia or its connections in visual processing.

Adynamic Aphasia: A Transcortical Motor Aphasia with Defective Semantic Strategy Formation

Adynamic aphasia is a form of transcortical motor aphasia characterized by sparse but otherwise normal spontaneous speech that may improve when concepts are introduced by external stimuli. Akinesia, impaired concept formation, inertia of concept generation, a defective semantic network, damage or impaired access to the verbal output lexicon, and defective semantic strategy formation have been proposed to account for this disorder. We studied a patient with adynamic aphasia and frontal lobe systems dysfunction due to bilateral striatocapsular infarctions. The patient was not akinetic but did demonstrate inertia of concept generation that could be overcome with prompting. However, prompting did not improve the number of concepts generated. He demonstrated a generally intact verbal lexicon and semantic network and normal lexical priming. However, his ability to sort closely related items into different classes without prior cuing regarding the nature of the classes was defective. Although his verbal memory was normal, he appeared to use a serial rather than a semantic strategy to recall items. Finally, despite normal lexical priming, he was impaired on a letter fluency task. These results most clearly demonstrate a defect in semantic strategy formation but indicate an additional and possibly related deficit in concept formation and a partial deficit in lexical strategy formation. All of these deficits appear to reflect impairment in the hierarchical organization of knowledge specific to the task at hand. This appears to be a key component of executive functions supported by frontal lobe systems.

Apraxia and motor-skill acquisition in Alzheimersdisease are dissociable

Many patients with Alzheimers disease (AD) are apraxic and the apraxia has been posited to be related to a loss of movement representations. Whereas patients with Alzheimers disease have been reported to demonstrate normal motor learning on a rotor pursuit skill acquisition task, it is unknown whether AD subjects who are apraxic demonstrate normal skill-learning. We tested subjects with probable AD and normal controls on a rotor pursuit task. We also tested the AD subjects for ideomotor apraxia. Subjects with AD who were apraxic had normal motor learning. In addition, praxis score did not correlate with performance on the skill-acquisition task. The results suggest that ideomotor praxis and motor learning are at least partly dissociable.

Physostigmine pharmacotherapy for anomia

Abstract Cholinergic neurons may influence the neural networks that subserve language. To learn if chollnergic drugs enhance the ability of anomic aphasic patients to name objects, we conducted studies of physostigmine and lecithin in three patients with anomia due to focal brain lesions. The flrst patient studied was amnestic and anomic, and presumed to be cholinergic-deficient due to a basal forebrain lesion. In open and blinded trials confrontation naming improved consistently with treatment but other cognitive measures did not. We subsequently tested two additional anomic patients with lesions outside the basal forebrain. We found improvement in confrontation naming but not other measures of cognition or mood during open-label physostigmine treatment. Physostigmine appears to improve naming in patients with anomia.

Herpes simplex virus encephalitis following corticosteroids and cranial irradiation

To the Editor: We thank Fodor et al. for expanding our appreciation of the clinical spectrum of herpes simplex virus encephalitis (HSVE).1 Fodor et al. noted that patients with HSVE can present with mild or atypical symptoms, without the characteristic pleocytosis in the CSF, and that HSVE can be precipitated by the administration of corticosteroids. Other authors have also suggested that HSVE should be considered an opportunistic infection in cases in which patients are immunocompromised.2,3 The increasing appreciation of this fact has been enabled in part by the ease of diagnosing HSVE from CSF with the introduction of new PCR techniques. We present a 42-year-old woman with intracranial metastases of breast cancer treated for 1 month with steroids and cranial irradiation. The patient is a right-handed woman who presented with facial numbness and falling to the right 4 years after completing initial treatment for breast cancer. She had been treated with lumpectomy, chemotherapy, and local radiation 4 years previously and, until shortly before presentation, had no signs of persisting or recurrent disease. Her mental status was normal. She had numbness in V1, V2, and V3 on the right and …

MS and cognition and APOE: The ongoing conundrum about biomarkers

The recognition of the importance of cognitive impairment in individuals with multiple sclerosis (MS) is increasing. Cognitive difficulties can occur early in the disease course1 and affect up to 65% of cases.2 Although the etiology of cognitive impairment in MS remains controversial, less debate exists regarding the significant impact on quality of life and disability.3 The early identification of cognitive impairment may provide opportunities for intervention. To this end, the article by Shi et al.4 is of interest as it reports an association of the APOE e4 allele and cognitive impairment in MS, especially among younger individuals. How early the findings appear and how subtle they are continue to vex clinicians. As discussed by Shi et al., …