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PubMed2002

Chiari I malformation in the very young child: the spectrum of presentations and experience in 31 children under age 6 years.

INTRODUCTION: The entity of hindbrain herniation without myelodysplasia in the very young child has been poorly described. A retrospective analysis of children diagnosed with Chiari I malformation (CM I) before their sixth birthday is presented. METHODS: Since 1985, 31 children with CM I (0.3-5.8) years of age have been diagnosed at University of Iowa Hospitals and Clinics. Their records were reviewed for presenting symptoms, signs, radiographic findings, treatment, complications, and outcome. RESULTS: The average age at diagnosis was 3.3 years. Sixteen patients were under age 3. Chief presenting complaints included impaired oropharyngeal function (35%), scoliosis (23%), headache or neck pain (23%), sensory disturbance (6%), weakness (3%), and other (10%). Sixty-nine percent of children under age 3 had abnormal oropharyngeal function. Three patients under age 3 (19%) had undergone fundoplication and/or gastrostomy before diagnosis of CM I. Common physical findings included abnormal tendon reflexes (68%), scoliosis (26%), abnormal gag reflex (13%), and normal examination (13%). Vocal cord dysfunction (26%, all under age 3) and syringohydromyelia (52%) were also seen. Twenty-five patients were treated surgically at our institution with posterior fossa decompression, duraplasty, and cerebellar tonsillar shrinkage. Three patients were lost to follow-up. Ninety-one percent of patients reported improved symptomatology at last follow-up (mean: 3.9 years). Three patients required reoperation for recurrence of symptoms. Syringomyelia improved in all patients. Scoliosis resolved in 2 of 8 patients, improved in 5, and stabilized in 1. There was no permanent morbidity from surgery. DISCUSSION: We show that children with Chiari I abnormality are very likely to present with oropharyngeal dysfunction if under age 3, and either scoliosis or headache or neck pain worsened by valsalva if age 3 to 5. These symptoms are very likely to improve after Chiari decompression, which can be done with low morbidity. CONCLUSIONS: Very young children presenting with oropharyngeal dysfunction, pain worsened by valsalva, or scoliosis should prompt the clinician to consider CM I as a possible cause.

Arnold-Chiari Malformation↗
PubMedDate not supplied

[Electrophysiological analysis of various brain stem reflexes in multiple sclerosis].

An electrophysiological study of "blink reflex" and "jaw reflex" was carried out on 20 sicilian patients with "definited" Multiple Sclerosis. The R1 component of the "blink reflex" was abnormal in 13 patients on 20 (65%), the R2 component in 8 patients on 20 (40%). Considering together the R1 and R2 responses, the abnormal percentage was 75%. The "jaw reflex" showed abnormal responses in 5 patients on 20 (25%). Considering both the "blink reflex" and "jaw reflex", the pathological percentage was 75%, in order that no patients had isolated changes of the "jaw reflex". The simultaneous study of the two reflexes does not increase the probability to prove pathological responses. The frequency of the clinically silent brain-stem lesions in our patients was not substantially different from that showed by other authors on different populations.

Adolescent↗
PubMed1991

Interaction between the blink reflex and the abnormal muscle response in patients with hemifacial spasm: results of intraoperative recordings.

Patients with hemifacial spasm (HFS) have an abnormal muscle response (AMR) that can be elicited by stimulating one branch of the facial nerve and recording electromyographically from muscles innervated by other branches of the facial nerve. In addition, the R1 component of the blink reflex can be elicited from the affected side in patients with HFS who are undergoing microvascular decompression (MVD) operations under inhalation anesthesia. A synkinetic component of the blink reflex response that corresponds to the R1 component can be recorded from the mentalis muscle. In the present study we show that the blink reflex elicited by electrical stimulation of the supraorbital nerve can suppress the AMR elicited by electrical stimulation of the temporal branch of the facial nerve in patients with HFS when the interval between stimulation of the supraorbital nerve and stimulation of the temporal branch of the facial nerve (interstimulus interval, ISI) is such that the blink reflex response would appear later than the AMR if they had been elicited independently. Within a short range of ISIs the two responses suppress each other partially or totally. We find evidence that the suppression of the AMR is the result of an interaction in the facial motonucleus. We believe that the results of the present study support the hypothesis that the facial motonucleus is hyperactive in patients with HFS, and we suggest that the AMR is a result of backfiring from the facial motonucleus and that it may thus be an exaggerated F-response.

Blinking↗
PubMed1999

Vascular abnormalities in acute reflex sympathetic dystrophy (CRPS I): complete inhibition of sympathetic nerve activity with recovery.

BACKGROUND: Reflex sympathetic dystrophy/complex regional pain syndrome type I (RSD/CRPS I) is a painful neuropathic disorder that may develop as a disproportionate consequence of a trauma affecting the limbs without overt nerve injury. Clinical features are spontaneous pain, hyperalgesia, impairment of motor function, swelling, changes in sweating, and vascular abnormalities. OBJECTIVE: To investigate pathophysiological mechanisms of vascular abnormalities in RSD/CRPS I. DESIGN: Case study. SETTING: Autonomic test laboratory at a university hospital. PARTICIPANTS: A patient with an early stage of RSD/ CRPS I of the upper limb and 2 healthy control subjects. INTERVENTIONS: Cutaneous sympathetic vasoconstrictor innervation was assessed by measuring cutaneous blood flow (laser Doppler flowmetry) and skin temperature (infrared thermometry). To quantify sympathetic vasoconstrictor function, phasic (induced by deep inspiration) and tonic (induced by controlled thermoregulation) sympathetic reflexes were analyzed. Venous norepinephrine levels were determined bilaterally. The same tests were performed in the controls after induction of cutaneous antidromic vasodilation produced by histamine dihydrochloride application. MAIN OUTCOME MEASURE: Sympathetic cutaneous vasoconstrictor function in RSD/CRPS 1. RESULTS: Two weeks after the onset of RSD/CRPS I, skin temperature on the affected side was higher (close to core body temperature) than on the contralateral side at room temperature and during controlled thermoregulation, indicating maximal vasodilation. Phasic and tonic stimulation of cutaneous vasoconstrictor neurons did not induce a decrease of skin blood flow or temperature on the affected side but were normal on the contralateral side. Venous norepinephrine levels were lower on the affected side. Parallel to clinical improvement, loss of vasoconstrictor function completely recovered within weeks. Results of investigations in healthy subjects ruled out the possibility that antidromic vasodilation caused by activation of nociceptive afferents is responsible for the complete depression of sympathetic vasoconstrictor reflexes. CONCLUSIONS: Demonstrated for the first time is a complete functional loss of cutaneous sympathetic vasoconstrictor activity in an early stage of RSD/CRPS I with recovery. The origin of this autonomic dysfunction is in the central nervous system.

Autonomic Nervous System↗
PubMedDate not supplied

Assessment of sensorial oral stimulation in infants with suck feeding disabilities.

A non-randomized single blind study was undertaken to determine the clinical and physiological changes in suck feeding after sensorial oral stimulation, in fourteen patients age 9 to 210 days old with sucking alterations. Patients lacked at least one of the five oral reflexes, plus two or more abnormal sucking sings or at least one abnormal sucking sign, plus two or more abnormal oral reflexes. Oral sensorial therapy was performed thrice daily for five days. The number of absent oral reflexes, number of abnormal sucking signs, volume of milk for nursing and sucking rate, were registered. Differences of medians were tested using Freidman's test and differential of proportions using Cochran's Q test. After therapy, oral reflexes were recovered (2, 0-4 vs. 5,5-5, p = 0.0000, median rank of absence oral reflexes) and the number of abnormal sucking signs decreased (6,1-9 vs. 1, 0-4; p = 0.0000). There were statistically significant improvements in patients who had lost launch up nipple ability (p = 0.005), delay at the beginning of sucking (p = 0.0022), drawing of milk from the mouth (p = 0.0001), cyanosis (p = 0.0084), weaning (p = 0.0004) and prolonged sucking (p = 0.0038). Even in patients with moderate improvement, no statistical differences were observed in nipple rooting (p = 0.09) and coughing (p = 0.09). No changes were observed in patients who had cried (p = 0.31) and spitted (p = 0.51) during feeding. At the end of therapy, volumes of consumed milk were increased at each feeding (10 ml, 0-40 vs. 50 ml, 25-60; p = 0.0001). Sucking rates also increased (22 sucks/minute, 10-35 vs. 40.5, 35-48; p = 0.0044). Oral sensorial and motor stimulation normalise oral motor reflexes, diminish the clinical abnormal sucking signs and increase milk volumes ingested for nursing.

Bottle Feeding↗
PubMedDate not supplied

Abnormalities of the acoustic reflex in multiple sclerosis.

Acoustic reflect morphology was examined in 122 patients with a diagnosis of definite multiple sclerosis. Abnormality in some dimension of acoustic reflex morphology was observed in 75 per cent of the study population. The most commonly observed abnormality was an alteration in one or more of the three relative amplitude indices (afferent, efferent, or central pathway index). Other abnormalities included delayed onset latency, delayed offset latency, reduction in absolute amplitude, and threshold elevation.

Adolescent↗
PubMed1993

Rabbits with a genetic impairment in baroreceptor reflex sensitivity show abnormal renal haemodynamics and proximal tubular sodium reabsorption in response to a saline infusion.

OBJECTIVE: To compare renal haemodynamics and proximal tubular sodium reabsorption (PTSR) in response to an acute intravenous saline infusion in rabbits bred for genetic differences in cardiac baroreflex sensitivity (BRS). Rabbits with low BRS increase their blood pressure significantly on a high-salt diet, in association with an initial delay in sodium excretion. It was hypothesized that this could occur through an impaired baroreflex regulation of renal sympathetic nerve activity. This, in turn, would alter renal blood flow and PTSR. DESIGN: Experiments were performed in two groups of normotensive male rabbits (n = 10 per group), one of which had high BRS (> 5 beats/min per mmHg; group I) and one of which had low BRS (< 4 beats/min per mmHg; group II). Effective renal plasma flow (ERPF) was measured by para-aminohippuric acid clearance, and PTSR by the lithium clearance technique. Sodium, lithium, para-aminohippuric acid and glomerular filtration rate were measured from urine samples collected every 30 min (for 90 min) via an indwelling bladder catheter, during a control infusion of glucose (30 mg/ml) NaCl (1.8 mg/ml), and for 2 h after a threefold increase in NaCl. RESULTS: Group I rabbits increased their ERPF by approximately 40%, in response to saline, and doubled their sodium and lithium clearances within the 2 h, but those in group II did not change their cation excretion or their ERPF significantly during this period. Blood pressure did not increase in either group. CONCLUSIONS: A genetic impairment in BRS may be responsible for the inadequate depression of renal sympathetic nerve activity, which results in a failure to increase ERPF and suppress sodium reabsorption in the proximal tubule in response to salt loading.

Absorption↗
PubMed2002

H reflexes and F waves. Fundamentals, normal and abnormal patterns.

H reflexes and F waves have become integral parts of the electrodiagnostic examination in general, and nerve conduction studies in particular. They supplement the sensory and motor conduction studies by assessing the entire nerve segments including proximal portions of the motor and sensory axons. H reflexes and F waves have their own advantages and limitations, similarities and differences. These "late" responses are useful in patients with radiculopathies, plexopathies, and peripheral polyneuropathies, including the Guillain-Barre syndrome. They are also helpful in spinal cord disorders.

Brachial Plexus Neuropathies↗
PubMed2000

Neurologic evaluation of workers previously diagnosed with solvent-induced toxic encephalopathy.

We examined 52 railroad workers with long-term occupational solvent exposures (average 22 years duration) who had been previously diagnosed by others as having solvent-induced toxic encephalopathy. All described episodes of transient intoxication associated with occupational solvent exposure. Persistent symptoms developed, an average, 16 years after exposure onset and included impaired memory (38), altered mood (21), imbalance (18), and headache (17). Thirteen workers had mild mental status abnormalities, but none fulfilled conventional clinical criteria for encephalopathy or dementia. None had abnormal blink reflex (51) or abnormal electroencephalographic (39) studies. Eight of 47 magnetic resonance imaging studies showed evidence of scattered ischemic lesions among workers with known diabetes mellitus (2), elevated blood pressure (4), or peripheral vascular disease (2). One magnetic resonance imaging scan showed mild cortical atrophy. In stepwise multiple linear and logistic regression models, no statistically significant (P < 0.05) dose-response relationships were found between exposure duration and symptoms or signs that were suggestive of encephalopathy. However, the number of symptoms (P < 0.001) and the number of signs (P = 0.05) were associated with current use of central nervous system-active medications. Further, lower Mini-Mental Status Examination scores were associated with a history of alcohol abuse (P = 0.01) and lower educational level (P = 0.03). The number of chief symptoms involving memory, mood, balance, or headache differed significantly among workers in different geographic sites (F(3.48) = 2.94, P = 0.04), a finding that was not explained by job title or exposure duration. There also was a significant (P = 0.0001) inverse relationship between initial exposure year (r2 = 0.60) or total years of exposure through 1987 (r2 = 0.56) and interval to major neurologic symptom onset, suggesting that factors other than solvent exposure account in part for worker complaints. We found no objective neurologic evidence supportive of toxic encephalopathy or any other uniform syndrome among these individuals, and most complaints were explained by neuropsychological factors or conditions unrelated to occupational solvent exposure.

Adult↗
PubMed1997

Macrocerebellum: neuroimaging and clinical features of a newly recognized condition.

Other than hamartomatous enlargement of the cerebellum as in Lhermitte-Duclos syndrome, diffuse enlargement of the cerebellum is not clearly described. We report four patients (ages 9 months to 2 years) with diffusely enlarged cerebelli as identified by measurement of the cerebellum and comparison to age appropriate normal values. The cerebellar measurements were determined in absolute numbers and expressed as ratios of cerebellum to whole brain and supratentorial brain. The clinical features of these four children (3 boys, 1 girl) consistently include global developmental delay, tone abnormalities, preserved reflexes, delayed or abnormal maturation of the visual system (oculomotor apraxia), and deficient or delayed myelination of cerebral white matter. The etiology of the macrocerebellum is unknown but we propose that the cerebellum is responding to the elaboration of growth factors intended to augment the slow development of cerebral structures. Regardless of the etiology, the finding of a macrocerebellum appears to allow the clinician to predict the clinical features of the patient and probably represents a marker for disturbed cerebral development.

Brain↗
PubMed2005

The INFIR Cohort Study: investigating prediction, detection and pathogenesis of neuropathy and reactions in leprosy. Methods and baseline results of a cohort of multibacillary leprosy patients in north India.

The aim of this study was to find predictors of neuropathy and reactions, determine the most sensitive methods for detecting peripheral neuropathy, study the pathogenesis of neuropathy and reactions and create a bank of specimen, backed up by detailed clinical documentation. A multi-centre cohort study of 303 multibacillary leprosy patients in Northern India was followed for 2 years. All newly registered MB patients requiring a full course of MDT, who were smear positive and/or had six or more skin lesions and/or had two or more nerve trunks involved, were eligible. A detailed history was taken and physical and neurological examinations were performed. Nerve function was assessed at each visit with nerve conduction testing, warm and cold detection thresholds, vibrometry, dynamometry, monofilaments and voluntary muscle testing. Because the latter two are widely used in leprosy clinics, they were used as 'gold standard' for sensory and motor impairment. Other outcome events were type 1 and 2 reactions and neuritis. All subjects had a skin biopsy at registration, repeated at the time of an outcome event, along with a nerve biopsy. These were examined using a variety of immunohistological techniques. Blood sampling for serological testing was done at every 4-weekly clinic visit. At diagnosis, 115 patients had an outcome event of recent onset. Many people had skin lesions overlying a major nerve trunk, which were shown to be significantly associated with an increased of sensory or motor impairment. The most important adjusted odds ratios for motor impairment were, facial 4.5 (1.3-16) and ulnar 3.5 (1.0-8.5); for sensory impairment they were, ulnar 2.9 (1.3-6.5), median 3.6 (1.1-12) and posterior tibial 4.0 (1.8-8.7). Nerve enlargement was found in 94% of patients, while only 24% and 3% had paraesthesia and nerve tenderness on palpation, respectively. These increased the risk of reactions only marginally. Seven subjects had abnormal tendon reflexes and seven abnormal joint position sense. In all but one case, these impairments were accompanied by abnormalities in two or more other nerve function tests and thus seemed to indicate more severe neuropathy. At diagnosis, 38% of a cohort of newly diagnosed MB leprosy patients had recent or new reactions or nerve damage at the time of intake into the study. The main risk factor for neuropathy found in this baseline analysis was the presence of skin lesions overlying nerve trunks. They increased the risk of sensory or motor impairment in the concerned nerve by 3-4 times. For some nerves, reactional signs in the lesions further increased this risk to 6-8 times the risk of those without such lesions. Patients with skin lesions overlying peripheral nerve trunks should be carefully monitored for development of sensory or motor impairment.

Adolescent↗
PubMed1991

[Abnormalities in cough reflex].

Enzymes degrading peptides may participate in the regulation of the cough reflex. Thus, decreases in enzyme activities may enhance cough reflex and a decrease in cough reflex may lead to aspiration pneumonia. Down- and up-regulation of cough reflex is important for the understanding of cough reflex.

Aging↗