PubMed Health⌕ Search

Biomedical subjects

Natan Gadoth

Publications and source records attributed to Natan Gadoth.

At least 19 recordsLinked to original sources
PubMed2006

A rare saccade velocity profile in Stiff-Person Syndrome with cerebellar degeneration.

Stiff-Person Syndrome (SPS) is an immune-mediated disorder of the central nervous system characterized by muscle rigidity, episodic muscle spasms, and high titers of antibodies against glutamic acid decarboxylase (GAD). The presence of cerebellar ataxia in SPS is extremely rare, but occurs. Clinical observations of ocular motor abnormalities have been noted in a few SPS patients. The purpose of this study is to provide a detailed quantitative documentation of ocular motor abnormalities in a patient with SPS and progressive cerebellar signs. Detailed clinical assessment of a woman with SPS and precise eye movement recordings using the magnetic search coil technique was performed. In addition to other ocular motor abnormalities that included longer latencies for saccades, downbeat nystagmus, and loss of downward smooth pursuit, a rare saccade velocity profile consisting of multi-component saccades was observed. We postulate that these ocular motor findings are related to impairment of GABAergic neurotransmission because antibodies to glutamic acid decarboxylase (GAD-Abs) have been implicated in the pathogenesis of both SPS and some cases of cerebellar ataxia. In addition, this unusual saccadic velocity profile may have important implications for modeling the saccadic system and furthering a complete understanding of saccade generation.

Cerebellum↗
PubMed2006

Could steroids mask the diagnosis of cerebrotendinous xanthomatosis?

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive disorder of bile acid synthesis, caused by impaired hydroxylation of cholesterol side chains due to deficiency of the mitochondrial enzyme sterol 27-hydroxylase (CYP27A1), leading to accumulation of cholestanol and cholesterol in brain and other tissues. Elevated plasma cholestanol serves as a key marker for the clinical diagnosis of CTX. In the present report we describe a young man with CTX who was on high dose steroids for a misdiagnosed chronic inflammatory demyelinating polyneuropathy (CIDP) and had normal level of serum cholestanol. When steroids were discontinued, markedly elevated serum cholestanol was measured concomitant with marked clinical worsening. This observation may imply that steroids can lower plasma cholestanol, possibly by directly inducing residual CYP27A1 activity or by inducing alternative pathways for cholestanol elimination.

Achilles Tendon↗
PubMed2006

A head bulge.

Explore the source record for details and available documents.

Decompression, Surgical↗
PubMed2005

The neurology of cobalamin deficiency in an elderly population in Israel.

OBJECTIVES: To evaluate the neurological status in elderly subjects with cobalamin deficiency (CblD) compared with matched non-deficient subjects before and after cobalamin (Cbl) supplementation. METHODS: Participants completed a questionnaire on activities of daily living, level of education, medical history, alcohol, nicotine, caffeine, and medication usage and prior consumption of vitamins. They underwent a detailed programmed neurological evaluation which was repeated after 6-9 months of Cbl therapy. RESULTS: There were 113 subjects with blood Cbl < or =147 pmol/L, methylmalonic acid > or =0.24 mumol/L, and 212 nondeficient subjects (controls). The mean age of the patients and controls was 79.5 +/- 6.9 and 79.5 +/- 5.9 years, respectively. Fifty patients (44.4 %) and 56 controls (26.4%) were found to have mild sensory neuropathy (SN).When subjects with diabetes mellitus (DM) were excluded, however, only 30 (26.5%) patients and 23 (10.8 %) controls had SN. A history of confusional state was more common among the patients than among the controls (12.4 % and 3.3%, respectively) as was a low mini-mental state examination (MMSE) score (20.2% and 15.2%, respectively). No patient had clinical signs compatible with subacute combined degeneration (SCD). Supplementation of Cbl for 6-9 months did not alter the neurological findings,while the biochemical deficiency was corrected. CONCLUSIONS: Mild SN rather than SCD is the main neurological impairment in elderly people with CblD. Short-term supplementation of CbL can correct the biochemical deficiency without affecting the neurological impairment.

Aged↗
PubMed2005

Early clinical heterogeneity in choreoacanthocytosis.

BACKGROUND: Choreoacanthocytosis (CHAC) is a slowly progressive multisystem disorder with involuntary movements, cognitive decline, behavioral changes, seizures, and polyneuropathy caused by mutations in the VPS13A gene. OBJECTIVE: To describe the early clinical features and possible genotype-phenotype correlation in CHAC. DESIGN AND SETTING: Case series in a tertiary care center. PATIENTS AND MAIN OUTCOME METHODS: Choreoacanthocytosis was diagnosed in 3 patients of Jewish origin from 3 unrelated families. We reviewed their medical histories and performed molecular analysis by screening all 73 exons of VPS13A. RESULTS: Trichotillomania, hypertrophic cardiomyopathy, and idiopathic hyperCKemia, in 1 patient each, preceded the development of the full clinical spectrum of CHAC by 2 to 20 years. At diagnosis, 2 patients manifested signs of overt neuromuscular involvement and were homozygous for the 6059delC mutation, whereas 1 patient had only hyporeflexia and was homozygous for the EX23del mutation. Because only 1 of the 2 patients with 6059delC had cardiomyopathy, its relevance to CHAC is unclear. CONCLUSIONS: These findings extend the knowledge of significant early clinical heterogeneity in CHAC and suggest a possible genotype-phenotype correlation. Awareness of the early manifestations may prevent misdiagnosis and enable appropriate genetic counseling.

Adult↗
PubMed2005

The effect of age and structural lesions on postictal language impairment.

The duration of postictal language dysfunction following a temporal lobe complex partial seizure (TLCPS) is longer when the seizure originates in the dominant hemisphere. However, the effects of older age and the presence of a structural lesion ipsilateral to the area of origin of the seizure remain unknown. Postictal language delay (PILD) was analyzed in relation to age and presence of a structural lesion in 47 patients, 28 with dominant TLCPSs and 19 with nondominant TLCPSs (total 173 seizures). Mean ages of the groups were 32.5 years (range: 16-68) and 36.1 years (range: 21-50), respectively. Nonsclerotic structural lesions were found by magnetic resonance imaging in 13 patients, eight with seizures in the dominant hemisphere and five with seizures in the nondominant hemisphere. Age did not affect PILD regardless of the lateralization of the seizures. The presence of a structural lesion significantly prolonged PILD only in the patients with nondominant TLCPS (p = 0.019). In conclusion, the anatomical site of seizure onset may not be the only determinant of the nature of the postictal state. PILD can provide important information on seizure localization and spread.

Adolescent↗
PubMed2005

Cognitive function in idiopathic generalized epilepsy of childhood.

This study evaluated the cognitive profiles of children with idiopathic generalized epilepsy (IGE), uniformly treated with valproic acid with well-controlled seizures. Twenty-four were neuropsychologically evaluated. They comprised: 14 females, 10 males: 12 with generalized tonic-clonic seizures (GTCS), mean age 14y 4mo, SD ly 7mo, range 12y to 16y 4 mo; 12 with absence seizures (AS]) mean age 14y 5mo, SD ly 10mo, range 11y to 16y 4mo, with intellectual abilities within the normal range and age-appropriate scholastic skills, and 20 healthy controls (12 females, 8 males; mean age 14y 5mo, SD 1y 10mo, range 10y 7mo to 16y 7mo). As a group, children with IGE performed significantly poorer in all tests (non-verbal and verbal attention, verbal learning and memory, word fluency, and controlled sequential fine motor responses) excluding non-verbal memory. Analysis according to type of seizure revealed that both patient groups (AS and GTCS) had an attention deficit, whereas only children with AS showed deficits in verbal learning and memory, word fluency, and controlled fine motor responses. These results suggest a long-term risk of learning impairment for children with IGE, even if they have normal intelligence and their seizures are well controlled.

Adolescent↗
PubMed2005

Cortical activity of children with dyslexia during natural speech processing: evidence of auditory processing deficiency.

Children with dyslexia have difficulties with phonological processing. It is assumed that deficits in auditory temporal processing underlie the phonological difficulties of dyslectic subjects (i.e. the processing of rapid acoustic changes that occur in speech). In this study we assessed behavioral and electrophysiological evoked brain responses of dyslectic and skilled reading children while performing a set of hierarchically structured auditory tasks. Stimuli consisted of auditory natural unmodified speech that was controlled for the parameter of changing rate of main acoustic cues: vowels (slowly changing speech cues: /i/ versus /u/) and consonant-vowel (CV) syllables (rapidly changing speech cues: /da/ versus /ga/). Brain auditory processing differed significantly between groups: reaction time of dyslectic readers was prolonged in identifying speech stimuli and increased with increased phonological demand. Latencies of auditory evoked responses (auditory event related potentials [AERPs]) recorded during syllable identification of the dyslectic group were prolonged relative to those of skilled readers. Moreover, N1 amplitudes during vowel processing were larger for the dyslectic children and P3 amplitudes during CV processing were smaller for the dyslectic children. From the results of this study it is evident that the latency and amplitude of AERPs are sensitive measures of the complexity of phonological processing in skilled and dyslectic readers. These results may be signs of deficient auditory processing of natural speech under normal listening conditions as a contributing factor to reading difficulties in dyslexia. Detecting a dysfunction in the central auditory processing pathway might lead to early detection of children who may benefit from phonetic-acoustic training methods.

Acoustic Stimulation↗
PubMed2005

[Benign paroxysmal positional vertigo: who can diagnose it, how should it be treated and where?].

Benign Paroxysmal Positional Vertigo (BPPV) is a very common cause of vertigo that can affect any of the semicircular canals. Posterior canal BPPV, by far the most frequent form of BPPV, can be effectively treated by a number of different physical methods. During the last few years the diagnosis and treatment of BPPV became so popular that in our tertiary referral Dizziness Clinic we encounter many cases of over-diagnosis, misdiagnosis and maltreatment. This review describes the various types of BPPV and the appropriate diagnostic work-up and treatment, emphasizing the adequate management of uncommon presentations. All physicians who receive appropriate training in BPPV should be able to accurately diagnose posterior canal BPPV by performing the Dix-Hallpike positional test and treat it immediately by one of the physical maneuvers with a success rate of 70%-90%. Futhermore, appropriately trained physiotherapists should be able to treat these cases. Repeated physical maneuvers during a single treatment session seem to be clinically superior to a single maneuver. The published post-treatment measures are inconvenient and should be abandoned. Patients who fail to respond to a single treatment session or with frequent recurrences of BPPV can be instructed to perform a "self-treatment" maneuver. The diagnosis of the different subtypes of horizontal canal BPPV (geotropic and apogeotropic nystagmus) requires special skill since cerebellar and brainstem disorders might also cause horizontal positional nystagmus. Two methods of treatment are commonly used: a rolling maneuver of 270 degrees or 360 degrees ("barbecue maneuver") and the "forced prolonged position" with a success rate of about 70% after a few maneuvers. About 20% of cases of horizontal BPPV fail to respond to these treatments. The anterior canal variant of BPPV characterized by torsional downbeat nystagmus is very rare. In such cases a detailed neurological examination is mandatory in order to rule out other causes of downbeat nystagmus. The authors recommend that patients with suspected horizontal or anterior canal BPPV should be immediately examined by a neurologist and if no other neurological abnormality is found a referral to a specialized dizziness clinic should follow.

Diagnosis, Differential↗
PubMed2004

Is posttraumatic benign paroxysmal positional vertigo different from the idiopathic form?

BACKGROUND: Although head trauma is considered a common cause of benign paroxysmal positional vertigo (BPPV), clinical presentation and outcome of traumatic BPPV (t-BPPV) have not been systematically evaluated. OBJECTIVES: To compare the clinical presentation, patient's response to physical treatment, and outcome of patients with t-BPPV with those with the idiopathic form (i-BBPV). SETTING: Tertiary referral neuro-otology outpatient clinic. METHODS: We reviewed the clinical records of 247 consecutive patients with posterior canal BPPV during the years 1997 to 2000. All patients were diagnosed using the Dix-Hallpike test and treated using the particle repositioning maneuver. Patients with an onset of positional vertigo within 3 days of well-documented head trauma were included in the t-BPPV group. The outcome was compared with the outcome of 42 patients with i-BPPV who were similarly treated and followed up. RESULTS: Twenty-one (8.5%) of the 247 patients with BPPV fulfilled the diagnostic criteria for t-BPPV. The most common cause of head trauma was motor vehicle crash, documented in 57% of the cases; half of the patients additionally suffered from a whiplash injury. While the other causes were diverse, common falls were predominant. Only 2 of the patients involved in motor vehicle crashes experienced brief loss of consciousness. Sixty-seven percent of patients with t-BPPV required repeated physical treatments for complete resolution of signs and symptoms in comparison to 14% of patients with i-BPPV (P<.001). During a mean +/-SD follow-up of 21.7 +/- 9.7 months, 57% of t-BPPV patients and 19% of i-BPPV controls had recurrent attacks (P<.004). CONCLUSIONS: The nature and severity of the traumas causing t-BPPV are diverse, ranging from minor head injuries to more severe head and neck trauma with brief loss of consciousness. It appears that t-BPPV is more difficult to treat than i-BPPV, and also has a greater tendency to recur.

Adult↗
PubMed2003

Multiple sclerosis in children.

Multiple sclerosis (MS) is traditionally the domain of adult neurologists due to its characteristic presentation during early adult life. Although descriptions of infants with MS appeared in the beginning of the last century and the first autopsy was described even earlier, it was not until 1980 that childhood onset MS was recognized and subsequently well characterized. In spite of this, the awareness of pediatricians and pediatric neurologists to the occurrence of MS especially in infants and young children is still unsatisfactory. It is not infrequent that a meticulous, time consuming and costly search for metabolic and degenerative disorders other that MS is initiated before the diagnosis of MS is considered. This leads to a significant diagnostic and therapeutic delay in many young patients. Moreover, when the presentation is acute and characterized by confusion, seizures, CSF pleocytosis following a viral infection, a diagnosis of meningoencephalitis will be frequently reached. In this review, updated data on frequency, epidemiology, some special clinical and radiological features of childhood onset MS, outcome and treatment will be briefly discussed with the purpose of alerting physicians to the possibility of the occurrence of MS even in infants and young children.

Adolescent↗
PubMed2003

Linguistic processing in idiopathic generalized epilepsy: an auditory event-related potential study.

PURPOSE: Auditory processing of increasing acoustic and linguistic complexity was assessed in children with idiopathic generalized epilepsy (IGE) by using auditory event-related potentials (AERPs) as well as reaction time and performance accuracy. METHODS: Twenty-four children with IGE [12 with generalized tonic-clonic seizures (GTCSs), and 12 with absence seizures (ASs)] with average intelligence and age-appropriate scholastic skills, uniformly medicated with valproic acid (VPA), and 20 healthy controls, performed oddball discrimination tasks that consisted of the following stimuli: (a) pure tones; (b) nonmeaningful monosyllables that differed by their phonetic features (i.e., phonetic stimuli); and (c) meaningful monosyllabic words from two semantic categories (i.e., semantic stimuli). RESULTS: AERPs elicited by nonlinguistic stimuli were similar in healthy and epilepsy children, whereas those elicited by linguistic stimuli (i.e., phonetic and semantic) differed significantly in latency, amplitude, and scalp distribution. In children with GTCSs, phonetic and semantic processing were characterized by slower processing time, manifested by prolonged N2 and P3 latencies during phonetic processing, and prolongation of all AERPs latencies during semantic processing. In children with ASs, phonetic and semantic processing were characterized by increased allocation of attentional resources, manifested by enhanced N2 amplitudes. Semantic processing also was characterized by prolonged P3 latency. In both patient groups, processing of linguistic stimuli resulted in different patterns of brain-activity lateralization compared with that in healthy controls. Reaction time and performance accuracy did not differ among the study groups. CONCLUSIONS: AERPs exposed linguistic-processing deficits related to seizure type in children with IGE. Neurologic follow-up should therefore include evaluation of linguistic functions, and remedial intervention should be provided, accordingly.

Acoustic Stimulation↗
PubMed2003

Prolonged optokinetic stimulation generates podokinetic after rotation.

Previous studies showed that after prolonged stepping in place on the center of a rotating platform blindfolded subjects could no longer step in place on a firm floor. Instead, they invariably rotated themselves relative to space without perceiving their rotation, a phenomenon termed podokinetic after-rotation (PKAR). We speculated that prolonged optokinetic stimulation (OK) alone may generate similar PKAR. The purpose of this study was to evaluate the effects of prolonged OK on podokinetic (PK) responses. Ten healthy subjects participated in the study. After a control stepping test, they were seated in a circular closed cage and randomly (right or left) exposed to an OK (45 degrees /s) covering the whole visual field for 30 min. After this procedure, blindfolded subjects attempted to step in place on the stationary floor for 30 min. When trying to do so, all subjects turned relative to space without any perception of rotation. The direction of this optokinetically after-rotation (oPKAR) was opposite of that of the direction of OK. Mean peak velocity of oPKAR was 7.8 +/- 4.1 degrees /s, and it was reached after approximately 6 min of stepping. After that, there was a progressive velocity decay, which exhibited a discharging time constant on the order of 42 min toward a final positive asymptote of 3.1 degrees /s. We conclude that OK alone causes oPKAR. Long-term OK probably charges a storage element for podomotor activity with a relatively prolonged time constant. This novel form of neural interaction and adaptive plasticity may have significant implications for the treatment of vestibular and parietal lobe disorders.

Adaptation, Ocular↗
PubMed2002

Submandibular and sublingual salivary gland function in familial dysautonomia.

OBJECTIVE: Drooling in familial dysautonomia (FD) has been attributed to denervation supersensitivity. The aim of this study was to investigate submandibular and sublingual (SM/SL) gland function in FD. STUDY DESIGN: SM/SL saliva was collected from 15 children with FD and from 31 healthy control subjects. The protein and electrolyte content and the salivary flow rate were determined in each subject. RESULTS: Children with FD displayed significantly elevated outputs of chloride, potassium, calcium, phosphorous, magnesium, and total protein. Salivary flow rates were significantly increased. Phosphorous concentration was statistically low. These results imply SM/SL hyperfunction at the acinar and ductal levels. The concentration of lysozyme, the activity of amylase, and the output of both were similar in patients and control subjects. CONCLUSION: SM/SL gland hyperactivity is a newly described abnormality in FD. At the acinar level, this hyperactivity is expressed with increased fluid, electrolyte, and protein output, and at the ductal level, with increased ion secretion and absorption rate. These changes may be the result of ongoing parasympathetic denervation characteristic in FD.

Adolescent↗
PubMed2002

Hypnosis provoked pseudoseizures: a case report and literature review.

Only a few studies have been reported in which suggestion was used to provoke pseudoseizures (PS). In these studies PS were video EEG monitored, and saline injections were administered as placebo. This method may be somewhat unethical and carries a low success rate. The authors, two child psychiatrists (GZ and DS) and a neurologist (NG), applied hypnosis to provoke PS which were monitored by video-EEG. Pre-, intra- and post-ictal serum prolactin levels were determined. The first hypnotic session was diagnostic and for this reason featured controlled attempts to determine whether there might be childhood trauma material. The following sessions easily provoked PS during which the EEG was normal and pre-, intra- and post-ictal serum prolactin levels were identical and within normal values. We conclude that hypnosis (with informed consent) for PS monitored by video-EEG telemetry, seems to be an ethical, cheap and quite easy way to demonstrate PS.

Adolescent↗