In patients with the callosal type of anarchic-hand syndrome, the left hand often does not act as intended and counteracts the right hand. Reports are scarce about the underlying neurophysiological mechanisms. We report the case G.H. who developed the syndrome after infarction of the left arteria pericallosa. It has been suggested that the syndrome arises out of lacking inhibition from the dominant left hemisphere on the right hemisphere. Yet, in tests of spatial intelligence G.H. performed much better with his "anarchic" left hand than with his dominant right hand, similar to observations commonly reported in split-brain patients. Left-right manual choice responses and event-related EEG potentials to laterally presented stimuli were measured. Asymmetries were evident in G.H.'s behavior and EEG potentials, different from age-matched healthy participants (n = 11). His right-hand responses were fast and unaffected by incompatibility with stimulus location, whereas his left-hand responses were variable and accompanied by a large negative central-midline EEG potential, probably reflecting efforts in initiating the response. G.H.'s visual N1 component peaked earlier and was larger at the right than the left side of the scalp, and the P3 component was distinctly reduced at the right side. Both features occurred independent of side of stimulus presentation and side of responding hand. The effort indicated by the midline negativity and the asymmetrically reduced P3 might directly reflect G.H.'s lack of control on his right hemisphere's processing. The faster visual processing of the right hemisphere suggested by the N1 asymmetry might contribute to "anarchic" processing, making the right hemisphere process stimuli before control impulses exert their effect. These neurophysiological results tend to support the split-brain account which assumes that the syndrome arises by the lack of communication between hemispheres that act according to their respective competences. (C) 2011 Elsevier Inc. All rights reserved.

We report the clinical features of the original Chilean family with Kufor‐Rakeb syndrome (KRS) that led to the discovery of the ATP13A2 gene at the PARK9 locus. KRS is a rare juvenile‐onset autosomal recessive disease characterized by progressive Parkinsonism, pyramidal signs, and cognitive decline in addition to vertical gaze palsy and facial‐faucial‐finger minimyoclonus. Neurological and neuropsychological examination during a 10‐year period, videotaping, neuroimaging, and measurement of DNA methylation of the ATP13A2 promoter region were performed. The youngest 5 of 17 children of nonconsanguineous parents, carrying compound‐heterozygous ATP13A2 mutations, had normal development until ages ∼10 to 12 years, when school performance deteriorated and slowness, rigidity, and frequent falls developed. Examination revealed bradykinesia, subtle postural/action tremor, cogwheel rigidity, spasticity, upward gaze palsy, smooth pursuit with saccadic intrusions, and dementia. Additional signs included facial‐faucial‐finger minimyoclonus, absent postural reflexes, visual/auditory hallucinations, and insomnia. Levodopa response could not be fully judged in this family. T2* magnetic resonance imaging sequences revealed marked diffuse hypointensity of the caudate (head and body) and lenticular nucleus bilaterally. Disease progression was slow including epilepsy, cachexia, and anarthria. Four affected members died after 28.5 ± 5.5 (mean ± SD) years of disease. Two heterozygous carriers, the mother and eldest sibling, showed jerky perioral muscle contractions and clumsiness of hand movements. There was no significant correlation between DNA methylation of the ATP13A2 promoter region and disease progression. The marked caudate and lenticular nucleus T2*‐hypointensity suggests that KRS might belong to the family of neurodegenerative diseases associated with brain iron accumulation. © 2010 Movement Disorder Society.

Patients with homonymous hemianopia due to occipital brain lesions show disorders of visual search. In everyday life this leads to difficulties in reading and spatial orientation. It is a matter of debate whether these disorders are due to the brain lesion or rather reflect compensatory eye movement strategies developing over time. For the first time, eye movements of acute hemianopic patients ( n = 9) were recorded during the first days following stroke while they performed an exploratory visual-search task. Compared to age-matched control subjects their search duration was prolonged due to increased fixations and refixations, that is, repeated scanning of previously searched locations. Saccadic amplitudes were smaller in patients. Right hemianopic patients were more impaired than left hemianopic patients. The number of fixations and refixations did not differ significantly between both hemifields in the patients. Follow-up of one patient revealed changes of visual search over 18 months. By using more structured scanpaths with fewer saccades his search duration decreased. Furthermore, he developed a more efficient eye-movement strategy by making larger but less frequent saccades toward his blind side. In summary, visual-search behavior of acute hemianopic patients differs from healthy control subjects and from chronic hemianopic patients. We conclude that abnormal visual search in acute hemianopic patients is related to the brain lesion. We provide some evidence for adaptive eye-movement strategies developed over time. These adaptive strategies make the visual search more efficient and may help to compensate for the persisting visual-field loss.

Patients with homonymous visual field defects (HVFD) are often crucially disabled during self-guided visual exploration of their natural environment. Abnormal visual search may be related to the sensory deficit, deficient spatial orientation or compensatory eye movements. We tested the hypothesis that visual search in HVFD is purely determined by the visual-sensory deficit by comparing nine patients with HVFD due to occipital stroke in an acute stage to nine healthy subjects with technically simulated "virtual" homonymous visual field defects (vHVFD) and to nine controls with normal visual fields. The simulated gaze-contingent visual field defects in vHVFD subjects were individually matched to the patients' HVFD with respect to their size and side. Eye movements were recorded while subjects searched for targets among distractors and indicated target detection by clicks.All patients, in particular those with lesions involving the inferior occipito-temporal (fusiform) gyrus, but also those with small lesions restricted to the visual cortex, showed longer search durations than vHVFD subjects. This was tightly related to the higher number of fixations and particularly "re-fixations" (repeated scanning of fixated items). Working memory across saccades during the search was intact (no increased "re-clicks"). Scanpath strategies were similar in patients and vHVFD subjects. For both groups amplitude and frequency of saccades did not differ between the hemifields.In HVFD patients with acute occipital brain lesions, visual input failure does not fully account for abnormal visual search. It might either result from disconnections of the primary visual cortex to associated occipital and temporal brain areas or reflect an early stage of compensatory eye movements which differ from chronic HVFD patients. (C) 2009 Elsevier Ltd. All rights reserved.

Patients with homonymous hemianopia due to occipital brain lesions show disorders of visual search. In everyday life this leads to difficulties in reading and spatial orientation. It is a matter of debate whether these disorders are due to the brain lesion or rather reflect compensatory eye movement strategies developing over time. For the first time, eye movements of acute hemianopic patients (n= 9) were recorded during the first days following stroke while they performed an exploratory visual-search task. Compared to age-matched control subjects their search duration was prolonged due to increased fixations and refixations, that is, repeated scanning of previously searched locations. Saccadic amplitudes were smaller in patients. Right hemianopic patients were more impaired than left hemianopic patients. The number of fixations and refixations did not differ significantly between both hemifields in the patients. Follow-up of one patient revealed changes of visual search over 18 months. By using more structured scanpaths with fewer saccades his search duration decreased. Furthermore, he developed a more efficient eye-movement strategy by making larger but less frequent saccades toward his blind side. In summary, visual-search behavior of acute hemianopic patients differs from healthy control subjects and from chronic hemianopic patients. We conclude that abnormal visual search in acute hemianopic patients is related to the brain lesion. We provide some evidence for adaptive eye-movement strategies developed over time. These adaptive strategies make the visual search more efficient and may help to compensate for the persisting visual-field loss.

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The search coil technique is regarded as the gold standard in eye movement recordings. The manufacturers of scleral search coils (SSC) do not recommend using them longer than 30 min. The temporal limitations result from potential cornea damage and from irritations of the lid margins and palpebral conjunctiva which subjects perceive as unpleasant. Here we introduce a new coil-eyelid protection device (CEPD) which allows recording intervals up to 2 h with considerably reduced discomfort. Ophthalmic examinations and saccade recordings were used for comparison with the conventional SSC recording technique. In three experiments subjects were examined using SSCs with a commercially available cornea bandage lens on top of the search coil up to 120 min recording time. Ophthalmic testing revealed no apparent harmful effects on eyes or lid surface. Saccade parameters (main sequence) remained unchanged comparing SSC and CEPD recordings. Subjects rated less discomfort by using the CEPD. For the first time we show that SSC recordings can be extended over about 120 min without hazard to the eye, when using an eyelid protection lens. This advanced method allows new applications like eye movement recordings during sleep (rapid eye movements) or perceptional or motor learning tasks, e.g. saccade adaptation paradigms.