Is there a neurologist on this flight?

OBJECTIVE: To analyze the frequency of neurologic events during commercial airline flights and to assess whether onboard emergency medical kits are adequate for in-flight neurologic emergencies. METHODS: Collaboration of the Mayo Clinic's Departments of Emergency Medicine and Medical Transportation Service and the Division of Aerospace Medicine to provide real-time in-flight consultation to a major US airline that flies approximately 10% of all US passengers. We analyzed all medical events reported from 1995 to 2000 in a database that catalogs the air-to-ground medical consultations. All cases with potential neurologic symptoms were reviewed and classified into various neurologic symptom categories. The cost of diversion for each neurologic symptom was calculated and then extrapolated to assess the cost of neurologic symptoms to the US airline industry. RESULTS: A total of 2,042 medical incidents led to 312 diversions. Neurologic symptoms were the single largest category of medical incidents, prompting 626 air-to-ground medical calls (31%). They caused 34% of all diversions. Dizziness/vertigo was the most common neurologic symptom followed by seizures, headaches, pain, and cerebrovascular symptoms. Whereas seizures and dizziness/vertigo were the most common reasons for diversion, loss of consciousness/syncope was the complaint most likely to lead to a diversion. The estimated annual cost of diversions due to neurologic events is almost 9,000,000 dollars. CONCLUSION: Neurologic symptoms are the most common medical complaint requiring air-to-ground medical support and are second only to cardiovascular problems for emergency diversions and their resultant costs to the US airline industry. Adding antiepileptic drugs to the onboard medical kit and greater emergency medical training for in-flight personnel could potentially reduce the number of diversions for in-flight neurologic incidents.

Musical hallucinations associated with seizures originating from an intracranial aneurysm.

Hallucinations are defined as sensory phenomena in the absence of external sensory stimuli. Auditory hallucinations have been shown to arise from many different intracranial lesions, but seizures manifesting as musical hallucinations triggered by unruptured intracranial aneurysms are rare. We present a case of persistent, episodic musical hallucinations associated with seizures that led to the discovery of 2 small intracranial aneurysms. Typical electroencephalographic findings for seizure activity were observed but resolved after surgical clipping of the aneurysms. Concomitantly, the patient's hallucinations resolved. The literature on musical hallucinations is reviewed.

A pilot study of donepezil for memory problems in epilepsy.

We performed a pilot 3-month, open-label study of 5-10 mg donepezil, an anticholinesterase inhibitor, as treatment for memory problems in people with epilepsy. The Buschke Selective Reminding Test was administered at baseline and after 3 months of donepezil. In 18 completing patients, the total number of words recalled across learning trials was greater on donepezil (P = 0.4). No change was noted in attention, visual sequencing, mental flexibility, psychomotor speed, or reported quality-of-life scores. Mean 3-month seizure frequency at baseline was 2.70 ± 4.60, and during treatment, 3.06 ± 4.52 (P = 0.19, not significant). Two patients experienced increased tonic-clonic seizures. Side effects included diarrhea, stomach cramps, insomnia, depression, and blurred vision. Cholinergic medication is worthy of investigation as treatment for memory problems in people with epilepsy, but attention must be paid to possible exacerbation of seizures.

Parental report of sleep problems in children with attentional and learning disorders.

This study examined whether parents of children diagnosed with neurodevelopmental disorders (n = 79) report greater sleep-related problems in their offspring than do parents of normal community-based children (n = 86) on a research questionnaire developed to assess sleep and breathing problems, sleepiness, and behavioral problems. Clinical subgroups included: attention deficit/hyperactivity disorder (ADHD) (n = 43), learning disabilities (LD) (n = 11), and combined ADHD/LD (n = 25). Analyses revealed that parents of children with neurodevelopmental disorders report greater problems along all three dimensions than parents of normal control children. Sleep-related difficulties were reported at the same frequency across all three clinical subgroups. No significant difference between clinical and control groups was noted, however, in the reported length of sleep on weeknights. These preliminary findings suggest that sleep-related problems need to be routinely reviewed as part of the clinical evaluation of neurodevelopmental problems, because they may contribute to and/or exacerbate the behavioral manifestation of these disorders.

Suspected malingering and the Digit Memory Test: a replication and extension.

This study replicated a previous finding that suspected malingerers often perform at a level worse than patients with unequivocal brain dysfunction on the Digit Memory Test (DMT). In addition, it was demonstrated that patients suffering from aphasia as well as temporal and "frontal lobe" damage perform at a level higher than suspected malingerers. DMT performance of patients with true dementia, however, may be difficult to distinguish from suspected malingerers. If an individual is not demented (as judged by such tests as the BNI Screen for Higher Cerebral Functions) and performs at a level less than 95% across three trials of the DMT, the question of noncooperation with testing procedures or "malingering" should be considered.

Patient awareness of seizures.

In 31 consecutive patients who were admitted to an epilepsy monitoring unit, we prospectively determined whether the patients were aware of having seizures. On admission, all patients stated that they knew of at least some of their seizures. Eight of 23 with classifiable epileptic seizures recognized that they were occasionally unaware of their seizures. During telemetry, following full recovery of consciousness after each seizure, we asked the patients whether they had recently had a seizure. For control purposes, we asked the patients the same question at random times. Among patients with seizures, there were no false-positive answers. Only 6 of 23 (26%) of the patients with epilepsy were always aware of their seizures, including complex partial and secondarily generalized events, and 7 of 23 (30%) were never aware of any seizures. Self-reporting of seizures was unreliable: Patients reporting the lowest baseline frequency of seizures had the highest fraction of unrecognized seizures. Seizure awareness was lowest for patients with temporal lobe foci, especially on the left side. Patients with primarily generalized epilepsy were more likely to be aware of tonic-clonic seizures than were patients with secondarily generalized partial seizures. All four patients with nonepileptic attacks believed that they always knew of their seizures, but only three of the four patients actually did always know. Unrecognized seizures are frequent and should be considered in patient management and in studies.

Differential response characteristics in nonepileptic and epileptic seizure patients on a test of verbal learning and memory.

Investigators have found it difficult to separate patients with nonepileptic seizures (NES) from those with true epileptic seizures (ES) using quantitative measures of neuropsychological test performance. We examined qualitative response characteristics on the California Verbal Learning Test of 41 patients undergoing continuous video/audio-EEG monitoring in an effort to distinguish these patient groups (12 patients with left temporal [LT] foci, 11 with right temporal [RT] foci, and 18 with NES). NES patients explicitly recognized fewer target words compared with ES patients. In addition, NES patients rarely made false-positive errors, which resulted in failure to endorse a significant number of items on the recognition list. This response tendency is called a negative response bias. In contrast, LT patients endorsed a high number of items on the recognition test, which resulted in a positive response bias. RT patients demonstrated no consistent response tendency. In our sample, a negative response bias index (ie, a cutoff score < 0) showed a sensitivity of 61% and a specificity of 91%. We propose that failure to explicitly recognize words following repeated exposure may reflect aspects of psychological denial in NES patients. Response bias indices may thus help identify patients with NES and may begin to explain the psychological mechanisms underlying this complex disorder.

Diffuse cavernous hemangioma of the rectum and sigmoid.

A 65-year-old man with prolonged history of intermittent rectal bleeding due to a large hemangioma involving the distal colon underwent radiological evaluation. barium enema and computed tomography findings are illustrated and previous articles about this entity are briefly reviewed.

[Ideas on health and the environmental air. A comparative study between ancient and medieval medical texts]. / Ideas sobre la salud y el aire ambiental. Un estudio comparativo entre textos médicos antiguos y medievales.

The present work is designed to foster the understanding of traditional phenomena and the pattern of changes in the historical transmission of scientific knowledge from the classical antiquity until the Middle Ages. A comparative study is made here of the ideas championed by the classical Greek-Roman and the Hebrew medicine on one side and Maimonides's doctrine on the other, as regards the influence of the environmental air and the wind on the people's health. It results from the analysis of different texts that Maimonides had a very deep knowledge of the main works of both schools and that he was able to fully systematize the knowledge extant on that subject at his time while he did not bring in innovations of any special importance on the matter.

Immunophenotypic analysis suggests that granuloma faciale is a gamma-interferon-mediated process.

Granuloma faciale (GF) is an uncommon inflammatory dermatosis with characteristic clinical and histologic features. Very little is known about its pathogenesis. We used a battery of immunoperoxidase lymphocyte markers to study the population of hematopoietic cells present in a case of GF. The majority of non-myelocytic hematopoietic cells present were T-helper lymphocytes. The cells stained strongly with antibodies against the interleukin-2 receptor and with anti-lymphocyte functional antigen (LFA 1 alpha) antibodies. Overlying keratinocytes did not stain with ICAM-1 or HLA-DR, which may account for the presence of the Grenz zone in granuloma faciale. These findings suggest that a gamma-interferon-mediated process may play some role in the pathogenesis of this disorder.

Composition of cerumen lipids.

Lipids were extracted from "wet" cerumen and analyzed by quantitative thin-layer chromatography to determine their composition. The lipid fraction comprised 52% of the dry weight of cerumen and consisted of squalene (6.4%), cholesterol esters (9.6%), wax esters (9.3%), triacylglycerols (3.0%), fatty acids (22.7%), cholesterol (20.9%), ceramides (18.6%), cholesterol sulfate (2.0%), and several unidentified polar components (7.5%). In addition to the extractable lipids, the residue contained an additional 0.9% lipid that could be released only after saponification. This covalently bound lipid consisted of two unusual ceramides (63.4%), omega-hydroxyacids (27.7%) and nonhydroxy fatty acids (8.8%). The composition of this bound lipid resembled that recently found in human stratum corneum, which is thought to comprise a lipid envelope on the outer surface of the corneocytes. The free and covalently bound lipids may be significant determinants of the properties of cerumen. Desquamation of corneocytes and their associated lipids from the epidermal lining of the ear canal may make a major contribution to cerumen.

Renal expression of IGF I in hypersomatotropic states.

We examined insulin-like growth factor I (IGF I) gene expression in kidney in two models of hypersomatotropism, rats implanted with GH3 pituitary tumors, and rats administered exogenous growth hormone (GH). Both GH3 tumor-bearing rats and rats administered GH gained weight more rapidly than control animals, and had kidneys that were larger than those of controls. Tumor-bearing rats had increased levels of circulating IGF I. Glomeruli from tumor-implanted rats were sclerotic. Immunostainable IGF I was increased in medullary collecting ducts from tumor-bearing and GH-injected rats compared with kidneys from control animals. Levels of IGF I mRNA in kidneys of rats implanted with GH3 tumors and GH-injected rats were elevated compared with levels in kidneys from controls. Our findings demonstrate enhanced renal IGF I gene expression in hypersomatotropism. Stimulation of renal IGF I synthesis by GH could be causative of changes in renal function and renal size that occur in states of GH excess such as acromegaly.

The origin of alkanes found in human skin surface lipids.

Lipids extracted from human skin contain variable amounts of paraffin hydrocarbons. Although the composition of these alkanes strongly resembles petroleum waxes, it has been proposed that they are biosynthetic products of human skin. To investigate this question, skin surface lipids from 15 normal subjects were analyzed for the amount and composition of alkanes, using quantitative thin-layer chromatography and quartz capillary gas chromatography. The alkanes were found to constitute 0.5% to 1.7% of the skin lipids. Subjects differed greatly in the chain length distribution of their alkanes between 15 and 35 carbon atoms, and in the relative amounts of normal alkanes (like those in petroleum waxes) and branched chain alkanes (like those in petroleum lubricating oils). In 6 subjects, the alkane content of cerumen from each ear was examined to investigate whether alkanes arrive at the skin surface by a systemic route or by direct contact with environmental surfaces. No trace of alkanes was found in 11 of the 12 cerumen samples. Using a tandem accelerator mass spectrometer for carbon-14 dating, a combined sample of the skin surface alkanes was found to have a theoretical age of 30,950 years, similar to that of a sample of petrolatum. These analyses indicate that the alkanes found on the surface of human skin are mixtures of a variety of petroleum distillation fractions that are acquired by direct contamination from the environment.

Dual regulation of insulin-like growth factor I expression during renal hypertrophy.

We examined the regulation of insulin-like growth factor I (IGF-I) in kidney during the renal hypertrophy produced by two different experimental models: growth hormone treatment of hypophysectomized rats and compensatory hypertrophy subsequent to unilateral nephrectomy. Immunostaining for IGF-I in collecting ducts was enhanced in kidneys from growth hormone-repleted hypophysectomized rats, and the levels of IGF-I mRNAs were increased. In compensatory hypertrophy, no enhancement of the intensity of immunostaining was observed in kidneys of nephrectomized rats until 5 days postnephrectomy, at which time immunostainable IGF-I was increased markedly in medullary collecting ducts of hypertrophied kidneys compared with kidneys from sham-operated animals. No difference in steady-state levels of any IGF-I mRNA species was detected in whole kidneys or in collecting ducts from nephrectomized or sham-operated rats at any time postnephrectomy. Our findings demonstrate an increase in both IGF-I mRNA and in immunostainable IGF-I in collecting duct in the setting of growth hormone-induced renal hypertrophy but suggest that other, possibly translational, mechanisms underlie the induction of IGF-I synthesis during compensatory hypertrophy.

Focal expression of insulin-like growth factor I in rat kidney collecting duct.

To address the question of insulin-like growth factor (IGF) I localization and synthesis in kidney, we used two complementary experimental approaches: immunohistochemistry of fixed paraffin-embedded rat kidney sections; and measurement of IGF I mRNA in isolated components of the rat nephron, using a highly sensitive and specific solution hybridization assay. Immunostainable IGF I was localized exclusively to principal cells of cortical and medullary collecting ducts. Administration of growth hormone to hypophysectomized rats for 8 d resulted in enhanced immunohistochemical staining of IGF I within collecting ducts, but no detectable IGF I in other portions of the nephron. The abundance of IGF I mRNA was 7-12-fold higher in isolated papillary collecting ducts than in proximal tubules or glomeruli, and was enriched 10-fold compared with whole kidney. Our data demonstrate colocalization of IGF I and IGF I mRNA in the collecting duct, consistent with focal expression of the IGF I gene at this site.

Acute focal bacterial nephritis or renal abscess? A sonographic diagnosis.

The radiological and sonographic findings of acute focal bacterial nephritis in 3 patients are presented. The sonographic appearance of a poorly marginated mass in the renal cortex, with echo amplitude less than the normal parenchyma and with poor transmission, should suggest the diagnosis of acute focal bacterial nephritis in a patient with pyrexia and a tender renal mass. These features of poor echogenicity and lack of posterior enhancement contrast with the presence of patchy echogenicity and posterior enhancement found in the renal abscess. This is of surgical importance, as the management may tend to be conservative in the one and surgical in the other.