Characteristics and correlates of cognitive functioning following bone marrow transplantation.

Patients who undergo bone marrow transplantation (BMT) often report cognitive problems following treatment. This study used cognitive tests and a self-report measure of subjective cognitive complaints to determine (1) the rate of objective cognitive impairment in a sample of 65 BMT patients, and (2) the correspondence of patients' cognitive complaints to their actual cognitive performance. At 6 months following BMT, patients were assessed in seven cognitive domains--attention, verbal learning, verbal memory, visual memory, simple executive function, complex executive function, and psychomotor speed. Cognitive complaints were likewise assessed. In all, 51% had at least mild impairment (-1 standard deviation (s.d.) below published norms) in one or more cognitive domains, with 28% demonstrating moderate-to-severe impairment (-2 s.d.). Older patients and patients with lower IQ were more likely to score in the impaired range on objective cognitive tests, with males and the less educated showing trends toward scores in the impaired range. Younger patients made significantly more cognitive complaints. Total cognitive complaints were unrelated to average cognitive performance, and complaints in specific cognitive domains were largely unrelated to objective performance on corresponding domains. Findings suggest that patients who complain about their cognitive performance following BMT differ from those who experience actual deficits.

"Joubert syndrome" revisited: key ocular motor signs with magnetic resonance imaging correlation.

Joubert syndrome is characterized by episodic hyperpnea and apnea, developmental delay, hypotonia, truncal ataxia, ophthalmologic abnormalities, and vermian dysgenesis. We studied 15 patients with the diagnosis of Joubert syndrome to (1) more fully define the syndrome's clinical features, and (2) correlate the clinical features with magnetic resonance imaging (MRI) findings. Eight of 15 patients had a history of episodic hyperpnea and apnea. All patients had developmental delay and hypotonia. Of the 13 patients receiving detailed neuro-ophthalmologic evaluations, three had optic nerve dysplasia, pendular nystagmus, and gaze-holding nystagmus. All 13 patients had a normal vestibulo-ocular reflex based on head thrust, but had absent to poor ability to cancel the vestibulo-ocular reflex horizontally and vertically. Twelve of 13 patients had impaired smooth pursuit. Twelve of 13 patients had defects in initiation of saccades and quick phases. Two of the most consistent radiologic features were absent or hypoplastic posterior cerebellar vermis, and deformed midbrain and pontomesencephalic junction, which based on ocular motor physiology correlate with the vestibulo-ocular reflex cancellation/ pursuit defect and saccade initiation defect, respectively. As a result of midbrain, vermian, and superior cerebellar peduncle abnormalities, axial neuroimaging showed a unique "molar tooth" appearance of these structures. These results indicate that Joubert syndrome results from maldevelopment of the midbrain and cerebellar vermis, producing a pathognomonic sign on MRI.