Rehabilitation of reading and visual exploration in visual field disorders: transfer or specificity?

Reading and visual exploration impairments in unilateral homonymous visual field disorders are frequent and disabling consequences of acquired brain injury. Compensatory therapies have been developed, which allow patients to regain sufficient reading and visual exploration performance through systematic oculomotor training. However, it is still unclear whether the reading and visual exploration impairments require specific compensatory training for their improvement. We present the first cross-over rehabilitation study to determine whether the training-related performance improvements are task-specific, or whether there is a transfer of training-related improvements between reading and visual exploration. We compared the therapeutic effects of compensatory oculomotor reading and visual exploration training in 36 patients with unilateral homonymous visual field loss in a cross-over design. In addition, we explored whether the training sequence determines the overall treatment outcome. Our findings demonstrate that the training-related improvements in reading and visual exploration are highly specific and task-dependent, and there was no effect of training sequence.

Disease impact in chronic progressive external ophthalmoplegia: more than meets the eye.

We determined the extent of disease impact in 28 patients with genetically confirmed chronic progressive external ophthalmoplegia (CPEO) and compared the outcomes to those of matched myotonic dystrophy type I patients. CPEO patients reported a high frequency of severe fatigue (67.9%), pain (96.2%), depression (32.1%) and dependency in daily life (46.4%). The frequency and extent of depression were significantly higher than in DM1 patients (32.1% vs. 7.1%, p=0.040; mean Beck's depression inventory for primary care score 3.8±3.5 vs. 1.3±1.4, p=0.001), as were fatigue severity, pain intensity and extent of functional impairments. CPEO patients with polymerase gamma-1 mutations reported more functional impairments than those with mitochondrial DNA mutations. Disease impact was however not influenced by most clinical features. The present results help physicians to identify and to treat the factors that influence quality of life in CPEO patients and to provide symptomatic treatment where needed.

Vestibular perception in patients with acquired ophthalmoplegia.

Using a perceptual technique it is shown that patients with chronic external ophthalmoplegia have shortened vestibular responses. It is postulated that this is secondary to the retinal image slip experienced by these patients during head movements and a useful compensatory mechanism to suppress motion-induced sickness and spatial disorientation.

Elevated visual motion detection thresholds in adults with acquired ophthalmoplegia.

AIMS: To test the hypothesis that in patients with acquired chronic bilateral ophthalmoplegia, abnormal retinal image slippage during head movements would result in abnormal thresholds for visual perception of motion. METHODS: Five patients (two males and three females) with ophthalmoplegia were included in the study. The average age was 44 years (range 30-69 years). The aetiology of ophthalmoplegia was myasthenia gravis (MG; n=2), chronic progressive external ophthalmoplegia (CPEO; n=2), and chronic idiopathic orbital inflammation. Visual motion detection thresholds were assessed using horizontal and vertical gratings (spatial frequency) set at thresholds for visibility. The grating was then accelerated at 0.09 deg/s(2). The subject's task was to detect the drift direction of the stimulus. RESULTS: Visual motion detection thresholds were raised to a mean of 0.434 deg/s (SD 0.09) (mean normal value 0.287 deg/s (SD 0.08)) for horizontal motion; and to a mean of 0.425 deg/s (SD 0.1) (mean normal value 0.252 deg/s (SD 0.08)) for vertical motion. The difference in values for both horizontal and vertical motion detection were statistically significant when compared with age matched controls; p <0.023 for horizontal motion and p<0.07 for vertical motion (two tailed t test). CONCLUSION: Abnormally raised visual motion thresholds were found in patients with ophthalmoplegia. This may represent a centrally mediated adaptive mechanism to ignore excessive retinal slip and thus avoid oscillopsia during head movements.

Autosomal dominant progressive external ophthalmoplegia with multiple deletions of mtDNA: clinical, biochemical, and molecular genetic features of the 10q-linked disease.

Autosomal dominant progressive external ophthalmoplegia (adPEO) is a mitochondrial disease characterized by accumulation of multiple large deletions of mtDNA in patients' tissues. We previously showed that the disease is genetically heterogeneous by assigning two nuclear loci predisposing to mtDNA deletions: one on chromosome 10q 23.3-24.3 in a Finnish family and one on 3p 14.1-21.2 in three Italian families. To reveal any locus-specific disease features, we report here the clinical, biochemical, and molecular genetic characteristics of the 10q-linked disease in the single family reported to date. All seven patients and four asymptomatic subjects had ragged-red fibers and multiple deletions of mtDNA in their muscle. Ptosis and external ophthalmoplegia were the major clinical findings, and depression or avoidant personality traits were frequently, but not consistently, present in the subjects carrying mutant mtDNA. In six of the subjects with mutant mtDNA, the activities of the respiratory chain complexes I or IV, or both, were below or within the low normal range. Two autopsy studies revealed the characteristic distribution of mutant mtDNA in these patients: highest proportion of mutant mtDNA is found in different parts of the brain, followed by the skeletal and ocular muscle, and the heart.

[Moebius syndrome: therapeutic proposals from 2 cases]. / Le syndrome de Moebius: propositions thérapeutiques à partir de deux observations.

Moebius syndrome is a congenital bilateral palsy of the sixth and seventh cranial nerves. It results a total absence of facial expression and a severe strabismus. Social life is greatly disturbed. Other anomalies may be associated, especially other cranial palsies and Poland syndrome. The etiology of this syndrome isn't clearly established. Stem necrosis secondary to a vascular deficiency is often admitted. We report two observations. We emphasize the importance of a complete maxillo-facial treatment including maxillo-mandibular anomaly. Both patient underwent orthognathic surgery. The first one for class II and the second for class III anomaly. One patient underwent a facial reanimation by temporal muscle transfer. Orthognathic surgery must be realized prior to facial reanimation. A correction of the strabismus is possible. Moebius syndrome is a rare (200 observations) but very severe malformation. Maxillofacial surgery is able to improve the morphological and relational aspect of Moebius syndrome.

Impaired shifting of attention in Balint's syndrome.

We assessed the efficiency of attentional shifts across the horizontal and vertical axes of the visual field in a patient with Balint's syndrome caused by bilateral parieto-occipital infarctions. This was performed using an adaptation of Posner's peripheral cueing paradigm. In contrast to normal controls and patients with unilateral parietal lesions previously reported, this patient did not benefit from cues directing attention to the left or right visual field. She appeared to benefit only when the cues directed attention to the upper visual field. This suggests a defect in shifting attention that may occur following bilateral parietal lesions. We discuss the implications of these findings for the role of the parietal lobes in attentional processes and for our understanding of the behavioral abnormalities observed in Balint's syndrome.

Hemisphere asymmetry for eye gaze mechanisms.

To investigate left/right asymmetries in cerebral gaze mechanisms, eye deviation was evaluated in 90 patients following intracarotid sodium amylobarbitone injections. For right-handed subjects with left cerebral language dominance, the occurrence and severity of eye deviation were greater for right versus left hemisphere injections. In contrast, subjects with mixed cerebral dominance for language/handedness exhibited no left/right difference in the incidence of eye deviation. The results are consistent with right cerebral dominance for attentional/intentional mechanisms directed at external space. Further analysis suggests that the cerebral asymmetry for gaze may be due to an evolutionary loss of attentional/intentional mechanisms by the left cerebral hemisphere as language function developed.

Defective response to social cues in Möbius' syndrome.

A case of Möbius' syndrome is presented, with the mask-like facies and poor social relationships consistent with this diagnosis. Previous thought has implicated the inability to transmit facial cues as a cause for impoverished social functioning. The authors hypothesize that the inability to transmit is related to an inability to receive cues. They repeated a paradigm used previously to test ability to interpret facial cues. The otherwise intelligent patient could not perform a task previously performed by approximately 300 other subjects. These findings suggest that the rehabilitation of Möbius patients should include education in interpreting social cues.

Psychiatric aspects of progressive supranuclear palsy.

This paper describes four patients with undetected progressive supranuclear palsy who were referred to psychiatric facilities for treatment of late onset symptoms and signs attributed to primary psychopathology. However, subsequent neurological and neuropsychological evaluation established the diagnosis of progressive supranuclear palsy. In two patients, psychiatric symptoms preceded the onset of neurological deficits. It is our experience that because of presenting symptomatology, some patients with progressive supranuclear palsy will be referred for psychiatric consultation. The possibility of progressive supranuclear palsy should be considered in the differential diagnosis of late onset psychiatric syndromes.

Psychophysical assessment of a patient with Tolosa-Hunt syndrome.

Patients may complain of impaired vision and yet exhibit no abnormalities when tested with conventional tests of visual acuity. Some sensitive psychophysical tests used by psychologists and neurophysiologists to examine the function of the normal visual system are beginning to gain recognition as useful tools in clinical situations. They are particularly sensitive indicators of damage to the visual pathways. The results are presented of one such application which characterises the visual defects of a patient with a suspected diagnosis of Tolosa-Hunt Syndrome.

[Organic versus functional factors in the diagnosis of conversion disorders (author's transl)]. / Organische versus funktionelle Faktoren im Rahmen von Konversionsstörungen.

Conversion symptoms involving conspicous pseudoneurological signs of the motor system are very seldom today. To differentiate in these cases between organic and functional disturbances is highly difficult. Two patients are described. A 25 year old soldier with the symptomatology of a repetitive transverse lesion of the spinal cord and a 70 year old pensioner with a blepharospasm. They both showed an accompanying depression. Diagnostic criteria, psychodynamic models and especially the organic background of conversion symptoms are discussed.

[Trial and temptation in the interpretation of accommodative paralysis as a psychosomatic manifestation]. / Tentative et tentation d'interpréter comme une manifestation psychosomatique une paralysie de l'accommodation.

An adolescent, presented during 24 months an intermittent bilateral accommodation palsy. All the clinical tests were negative; a few peculiar aspects of the patient's character incited us to carry out, in parallel, a psychological research. The young man proved to be a mixed introvert, with Oedipal and familial problems. The assumption that accommodation palsy could have a psychological--although objectively unprovable motivation--is not in contradiction with the psychological research.