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Biomedical subjects

J E Jan

Publications and source records attributed to J E Jan.

At least 19 recordsLinked to original sources
PubMed2000

Clinical trials of controlled-release melatonin in children with sleep-wake cycle disorders.

This is the first study to examine effective doses of controlled-release (CR) melatonin in children with chronic sleep wake cycle disorders. All 42 subjects had severe neurodevelopmental difficulties. Initially, a randomized double-blinded cross-over design was used in 16 children, comparing the effectiveness of fast-release (FR) and CR melatonin. In the remainder of the patients, the CR melatonin was studied on a clinical basis. The effectiveness of treatment was assessed by sleep charts and clinical follow-up. Emphasis was placed on the judgement of the parents, who had guidance from the physicians. The average final CR melatonin dose in the 42 patients was 5.7 mg (2-12 mg). The studies showed that the FR melatonin was most effective when there was only delayed sleep onset, but CR formulations were more useful for sleep maintenance. Children appeared to require higher doses than adults.

Adolescent↗
PubMed2000

Cortical visual impairment in children with infantile spasms.

BACKGROUND: Infantile spasms are often associated with cortical visual impairment. METHOD: We report a series of 10 patients with infantile spasms, hypsarrhythmic electroencephalograms, and developmental delay, (ie, West syndrome), who presented with severe visual inattention despite a normal ocular examination. RESULTS: At follow-up (14 months to 6 years), 5 patients (50%) had no improvement in their visual behaviour. Although some degree of improvement was observed in the others, their visual function remained abnormal. All patients had moderate or severe mental retardation. CONCLUSIONS: The clinical features of West syndrome are reviewed, and the cause of the associated cortical visual impairment is discussed. Cortical visual impairment with infantile spasms is an important association, which pediatric ophthalmologists should recognize.

Diagnosis, Differential↗
PubMed1999

Melatonin treatment of non-epileptic myoclonus in children.

Oral melatonin (MLT) has been used by our Vancouver research group in the treatment of paediatric sleep disorders since 1991; slightly over 200 children, mainly with multiple disabilities, who frequently had seizures, have been treated. Three children with markedly delayed sleep onset due to recurring myoclonus were also referred for MLT treatment: two had non-epileptic, and one had epileptic and non-epileptic myoclonus. Low doses of oral MLT (3 to 5 mg) unexpectedly abolished their myoclonus and allowed them to sleep. There were no adverse effects. It appears that certain types of myoclonus, which might be resistant to conventional anticonvulsant medications, may respond to MLT but the mechanism of action is unclear. Further research on this novel treatment is urgently needed.

Anticonvulsants↗
PubMed1999

Neurologic abnormalities associated with persistent hyperplastic primary vitreous.

BACKGROUND: Persistent hyperplastic primary vitreous (PHPV) is usually a unilateral ocular abnormality not associated with other systemic findings. We describe 16 patients, 7 with unilateral and 9 with bilateral PHPV, in whom significant neurologic abnormalities were identified. METHODS: The clinical records of 16 children referred to the Visually Impaired Program at a university-affiliated children's hospital in Vancouver were studied from 1970 to 1996. Further investigations, including electroencephalography, computed tomography and pediatric neurologic evaluation, were performed to ascertain neurologic deficits. RESULTS: Neurologic abnormalities were identified in three of the children with unilateral PHPV (hemiparesis, impaired coordination and homonymous hemianopia) and seven of the children with bilateral PHPV (ataxia, impaired coordination, hypotonia, spastic quadriplegia, microcephaly and deafness). INTERPRETATION: The possibility of underlying neurologic abnormality should be considered in patients with PHPV, particularly those with bilateral disease. Referral to a pediatric neurologist may be appropriate.

Abnormalities, Multiple↗
PubMed1998

Unilateral alpha reactivity: an electroencephalographic finding in albinism.

Persons with various forms of albinism frequently have misrouting of their optic nerve fibers. Visual evoked potential (VEP) studies can confirm this because monocular stimulation tends to result in asymmetrical rather than symmetrical occipital response. This type of decussation abnormality is associated only with albinism. In the electroencephalogram (EEG) of normal subjects, unilateral eye opening or closing does not affect the frequency, reactivity, regulation, and symmetry of alpha rhythm. In contrast, in our study, 6 of 19 persons with oculocutaneous and ocular albinism responded to unilateral eye opening with contralateral disappearance or significant attenuation of their alpha rhythm. The most likely explanation of this phenomenon is that the visual pathway misrouting is complete or nearly complete in some children with albinism so that one rather than both occipital lobes receive visual information from each eye. This type of alpha behavior, like VEP studies, supports the diagnosis of albinism, and such testing can be easily performed during a routine EEG recording.

Adolescent↗
PubMed1998

Speech, cognition, and imaging studies in congenital ocular motor apraxia.

Detailed neurological, speech and language, psychological, and neuroimaging studies were carried out in eight children with the diagnosis of congenital ocular motor apraxia. The neurological examination showed clinical evidence of cerebellar vermis abnormality (hypotonia and truncal ataxia) in all cases. Neuroimaging studies suggested that the site of neuropathological disturbance of congenital ocular motor apraxia was the inferior vermis. Half of the subjects had associated speech apraxia. The most likely location of brain disturbance, which was responsible for the speech apraxia, was also an as yet undefined area of the vermis. Psychological testing consistently revealed visual-spatial difficulties. These may have been secondary to cerebellar pathology or to developmentally inappropriate sensory input caused by the abnormal saccades. Children with speech apraxia appear to be slightly more affected neurologically than those with normal speech.

Apraxias↗
PubMed1996

Visually impaired children with sensory defect nystagmus, normal appearing fundi and normal ERGS.

The differentiation of congenital motor nystagmus (CMN) from sensory defect nystagmus (SDN) in early life is a common diagnostic problem, since their wave forms are indistinguishable. A diagnosis of SDN is made when fundal or ERG abnormalities are present. CMN is generally diagnosed by exclusion. This approach can lead to late or incorrect diagnosis, and to the overlooking of important genetic implications. In addition, the classification of congenital nystagmus into pure motor and sensory types is inadequate. The authors present case reports illustrating this problem and suggest strict criteria for a diagnosis of CMN. They also point out that a miscellaneous group of rare disorders of the macula tend to be overlooked and misdiagnosed.

Adolescent↗
PubMed1996

Use of melatonin in the treatment of paediatric sleep disorders.

A group of Vancouver health professionals, including the authors, have studied the use of oral melatonin in the treatment of chronic sleep disorders in children with disabilities since the Fall of 1991. This review article is based on the first 100 patients, half of whom were visually impaired or blind. Children with neurological, neuropsychiatric, and developmental disabilities are predisposed to chronic sleep-wake cycle disturbances. Disorders such as blindness, deaf-blindness, mental retardation, autism, and central nervous system diseases, among others, diminish the ability of these individuals to perceive and interpret the multitude of cues for synchronizing their sleep with the environment. Melatonin, which benefitted slightly over 80% of our patients, appears to be a safe, inexpensive, and a very effective treatment of sleep-wake cycle disorders. The oral dose of fast release melatonin taken at bed-time ranged from 2.5 mg to 10 mg. Side effects or the development of tolerance have not been observed. Since the causes of sleep difficulties are extremely variable, not all children are candidates for treatment. For successful melatonin treatment, clinical experience is required, and the influences of other health problems and medications need to be considered. Further clinical and laboratory research in this field is imperative because melatonin treatment offers enormous health, emotional, social, and economic benefits to society, especially since multidisabled children with chronic sleep difficulties do not respond well to current therapeutic regimes.

Administration, Oral↗
PubMed1995

Familial paroxysmal kinesigenic choreo-athetosis in a child with visual hallucinations and obsessive-compulsive behaviour.

A teenage male is described, in whom Tourette Syndrome was suspected, which was later replaced by attacks of paroxysmal kinesigenic choreo-athetosis. He also exhibited bizarre, episodic perceptual distortions of his visual environment and manifestations of an obsessive-compulsive disorder. Carbamazepine treatment not only completely eliminated the recurring attacks of his choreo-athetosis but also, contrary to expectations, the visual disturbances and even the symptoms of his obsessive-compulsive disorder. Obsessive compulsive disorder should be searched for by direct questioning in all patients with basal ganglia disorders.

Adolescent↗
PubMed1994

Rapid cycling in severely multidisabled children: a form of bipolar affective disorder?

A debilitating, regularly recurring, biphasic disorder is described in 6 severely multidisabled children. It was characterized by several days of lethargy, withdrawal, loss of abilities, irritability, and hypersomnolence followed or preceded by a high-energy state for several days during which the children slept very little, at times were euphoric, had improved mental ability, and were hyperactive. These cyclic episodes had been present for years but unexpectedly disappeared in one child. The etiology is unknown, in spite of detailed neurologic, metabolic, and endocrine investigations. All patients had family histories positive for affective disorder. Melatonin treatment helped to regulate the coexisting chronic sleep disorders of 3 children but failed to eliminate the cycles. Antiepileptic drug treatment, lithium, sedatives, stimulants, tranquilizers, and light therapy were largely ineffective. The children's symptoms and signs fit the diagnostic criteria of a bipolar affective illness, as it was modified for patients with associated neurologic disability; therefore, the patients appeared to have a unique disorder that closely resembles or is a variant of rapid cycling affective disorder.

Adolescent↗
PubMed1994

The treatment of sleep disorders with melatonin.

Fifteen children (most of whom were neurologically multiply disabled) with severe, chronic sleep disorders were treated with 2 to 10mg of oral melatonin, given at bedtime. Nine had fragmented sleep patterns, three had delayed sleep onset and three others had non-specific sleep disturbance of unclear aetiology; all had failed to respond to conventional management. Nine patients had ocular or cortical visual impairment. The health, behavioural and social benefits of treatment were significant, and there were no adverse side-effects. While the response was not always complete, the study clearly showed that melatonin has an important role in the treatment of certain types of chronic sleep disorders.

Adolescent↗