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Intracranial dermoids are rare and are usually associated with cutaneous scalp lesions. Five hundred forty-two scalp lesions were treated in a 22-year period, and were associated with intracranial lesions in three cases. High-risk cases can be identified by clinical and radiological features, confirmed by a computed tomography scan, and then referred for neurosurgical treatment.
Aplasia cutis congenita is the congenital absence of skin. The majority of these defects involve the vertex of the scalp in the area overlying the sagittal sinus. The larger defects are predisposed to sudden lethal hemorrhage and require urgent closure. Local rotational scalp flaps are recommended for closure of the larger defects because they provide the most reliable coverage, eliminate the risk of infection and/or hemorrhage, and avoid the alopecia of secondarily healed wounds.
A full-term newborn infant with severe subcutaneous emphysema of the skull as a complication of vacuum extraction and scalp electrode wound is reported. We hypothesize that detachment of subcutaneous tissue and transmission of the negative pressure associated with the vacuum extraction resulted in entry of air through the scalp electrode wound.
Sequestrated meningocele of the scalp has seldom been reported and is difficult to diagnose. Clinically it resembles dermoid cyst, hemangioma, or alopecia; radiographs and computed tomographic scans reveal no cranial bone defect, and surgery discloses no communication with the cranial cavity. Histologically, the lesion is characterized by a loose arrangement of connective tissue in dermis and subcutis, associated with flattened cells around collagen fibers (meningothelial cells). Most examples are very vascular, sometimes mimicking angioma, and about one third contain small necrotic foci. The meningothelial nature of the lesion is shown by its architectural similarity to communicating meningocele, and its identical immunoperoxidase reactions with vimentin and epithelial membrane antigen. In the 12 cases reported herein, most lesions were small (1 to 1.5 cm), and all but one were noted at birth but usually not resected until the patient had reached age 1 to 4, and one not until the patient was 31 years of age. Five lesions were not midline. We have been unable on histologic grounds to determine whether meningoceles are communicating or sequestrated. Compared with 20 communicating meningoceles, the sequestrated lesions were usually smaller, found in slightly older patients, and much less likely to be associated with hydrocephalus. The local excision of scalp lesions in children should include a search for a small intracranial connection.
Total mercury levels (TML) were determined in 141 samples of maternal head and pubic hair and neonatal scalp hair. The mean mercury contents of maternal head and pubic hair were 1.88 and 1.10 mg kg-1, respectively, while the mean TML of neonatal hair was 0.11 mg kg-1. A statistically significant correlation was found between TMLs in neonatal and maternal hair. Significant inverse correlation was observed between the mercury concentration in the hair of a newborn and its birth weight. Reported findings provide evidence that the neonatal scalp hair mercury level may be a useful indicator of intrauterine exposure to mercury.
This 2-week, randomized, multicenter, investigator-blinded, parallel-group study was conducted to compare the efficacy and safety of augmented betamethasone dipropionate 0.05% lotion and clobetasol propionate 0.05% solution in the treatment of moderate-to-severe scalp psoriasis among 197 (193 assessable) healthy adult patients with at least 20% scalp-surface involvement. The patients received one of two treatments applied twice a day for 2 weeks. Signs and symptoms were evaluated at baseline, after 3 days (day 4), and after weeks 1 (day 8) and 2 (day 15) of treatment. As early as 3 days after treatment, scaling and induration were improved significantly faster by betamethasone dipropionate than by clobetasol propionate. Both treatments also reduced erythema and pruritus. Patients receiving betamethasone dipropionate had a significantly greater mean percent improvement in total sign/symptom scores (P < or = 0.015) at all visits and better mean global clinical response scores at the early visits (days 4 and 8) (P < or = 0.017). At the end of the study, only mild disease was present in both groups. Adverse events were reported by 34.0% and 36.4% of patients receiving betamethasone dipropionate and clobetasol propionate, respectively. All events were transient, most were mild and local, and no discontinuations resulted. The effects of treatment on the hypothalamic-pituitary-adrenal axis were not measured. In conclusion, augmented betamethasone dipropionate lotion and clobetasol propionate solution were equally effective, but betamethasone dipropionate lotion provided a faster onset of relief for scaling and induration, which may enhance patient compliance and patient satisfaction with treatment.
Analysis of variance (ANOVA) interactions involving electrode location are often used to assess the statistical significance of differences between event-related potential (ERP) scalp distributions for different experimental conditions, subject groups, or ERP components. However, there is a fundamental incompatibility between the additive model upon which ANOVAs are based and the multiplicative effect on ERP voltages produced by differences in source strength. Using potential distributions generated by dipole sources in spherical volume conductor models, we demonstrate that highly significant interactions involving electrode location can be obtained between scalp distributions with identical shapes generated by the same source. Therefore, such interactions cannot be used as unambiguous indications of shape differences between distributions and hence of differences in source configuration. This ambiguity can be circumvented by scaling the data to eliminate overall amplitude differences between experimental conditions before an ANOVA is performed. Such analyses retain sensitivity to genuine differences in distributional shape, but do not confuse amplitude and shape differences.
SSEPs to stimulation of the CPN at the knee and PTN, PN and SN at the ankle were recorded from 15 cephalic sites and compared in 8 normal subjects. The configuration, amplitude, peak latency and distribution of P27, N35 (CPN) and P37, N45 (PTN, PN and SN) were analyzed. The configuration and distribution of SSEPs to stimulation of the 3 nerves at the ankle were similar across subjects. Both P37 and N45 were greatest in amplitude at the vertex and at recording sites ipsilateral to the side of stimulation. At contralateral sites either negative (N37) or negative, positive, negative potentials were recorded. The peak latency of N37 was the same or slightly less than that of P37. CPN-SSEPs were lower in amplitude and their configuration and scalp distribution showed much greater intersubject variability. This suggests that complex mechanisms which variably interact with one another are reflected in scalp SSEPs to CPN stimulation at the knee. The larger amplitude plus the minimal intersubject variability in morphology and topography of PTN-SSEPs indicate that this nerve is the most suitable for routine clinical use.
We recorded motor evoked potentials (MEP) to transcranial magnetic stimulation from abductor pollicis brevis (APB), flexor carpi radialis (FCR), biceps brachii and deltoid muscles at rest and during slight voluntary activation. An 8-shaped coil connected to a Cadwell MES-10 magnetic stimulator was positioned over different scalp positions 1 cm apart. At least 24 stimuli were delivered at each location. Latencies of MEPs were compared with those obtained by electrical and magnetic stimulation during muscle activation. Progressively longer MEP latencies were obtained in 5 groups depending on the type and position of stimulation. The shortest latencies were obtained with (1) electrical stimulation during muscle contraction and (2) non-focal magnetic stimulation during muscle contraction; magnetic stimulation at rest produced longer latencies with stimulation of (3) an optimal position, (4) a suboptimal position, and (5) a non-optimal position. Mean latency differences between successive groups were 1.9, 2.0, 1.6, and 2.6 msec for APB. Similar latency differences were found for the other arm muscles. The results are compatible with the hypothesis that the different latencies evoked by stimulation at different scalp locations are determined by the summation at spinal motoneurons of excitatory postsynaptic potentials generated by successive numbers of I waves.
When uncorrelated random noise signals presented to the two ears suddenly become identical (coherent), a centrally located sound image is abruptly perceived and long latency scalp potentials are evoked. When the same signals are presented monaurally there is no perceived change and no potentials are evoked: hence the response must be purely a function of the binaural interaction. P70, N130 and P220 components were consistently recorded to both coherence and discoherence. N130 was usually largest at Fz and P220 at Cz. No potentials of shorter latency were identified, even after averaging 5000 or more sweeps. When the noise became coherent with an inter-aural time difference (delta T) of +/- 0.5 msec (giving rise to an off-centre sound image), the responses were of slightly longer latency and showed no significant asymmetries between C3 and C4. In binaurally coherent noise, delta T changes of +/- 0.5 or +/- 1.0 msec evoked similar responses which showed no significant asymmetries on the scalp. N130 was of longer latency when delta T was changed from +/- 0.5 msec to zero, as compared with the converse change. In view of the similarity of all these responses it is considered unlikely that they were due to specific populations of binaurally responsive cortical neurones. The N130 and P220 components are thought to be non-specific potentials which are elicited by any perceptible change in steady auditory stimulus conditions, due to a "mismatch" between the stimulus and the contents of a short-term auditory memory.
A method is described to compare two evoked potential scalp fields in order to decide if the two fields are the same or different. The method uses Efron's bootstrap technique which avoids potential errors due to assumptions about the underlying stochastic process. It is configured to focus only on the shape of the evoked potential scalp field. The method is applied to a simple visually evoked potential paradigm and results are compared to the chi-square test using data from 7 normal subjects.
Three cases of erosive pustular dermatosis of the scalp are reported. In all patients the dermatosis was characterized by pustular, erosive, and crusted lesions; in addition, two patients had areas of scarring alopecia. The results of laboratory tests, bacteriologic and mycologic investigations, and histopathologic examination were nondiagnostic. Although erosive pustular dermatosis of the scalp is characterized by a nonpathognomonic clinical and histopathologic picture, it probably represents a disease entity.
This paper examines three 'innovations in acumoxa' (zhenjiu) that were promulgated by the Chinese government during the Maoist periods of the Great Leap Forward (1958-61) and the Cultural Revolution (1966-76): acupuncture analgesia (zhenjiu mazui), scalp acupuncture (touzhen) and ear acupuncture (erzhen). They all bear features of Chinese and Western medical practice, a characteristic which has been exploited in Chinese politics of health. On the one hand, the innovations have been promoted for the nationalistic reason in virtue of their being inherently Chinese. On the other hand, by equating Western medical practice with science, they signify modernity and progressiveness. In the late eighties, all still enjoyed official backing. Although they were no longer exclusively practised in government hospitals, they still stood for what they had originally been promulgated. Acupuncture analgesia, while no more practised in the clinic, is still the prototype of a Chinese scientific therapy, now subject to biomedical research in laboratories. Scalp acupuncture, which never became widely known as a modern Chinese-Western innovation, is still being practised exclusively by skilled doctors. Ear acupuncture is now practised also outside government institutions, for the same reasons of being easily applied, easily learnt and extremely economical as it had originally been promulgated. Paradoxically, ear acupuncture, the most popular of the three, was 'discovered' outside China, by a French doctor, and is founded on the principles of reflexology, a therapy that the biomedical establishment does not consider scientific.
Human scalp hair follicles contain an enzyme system that metabolizes the carcinogen benzo[a]pyrene. The major ethyl acetate soluble metabolites are 7,8-dihydro-7,8-dihydroxybenzo[a]pyrene,9,10-dihydro-9,10-dihydroxybenzo[a]pyrene and 3-hydroxybenzo[a]pyrene. Addition of 1,1,1-trichloropropene-2,3-oxide (TCPO), an inhibitor of epoxide hydratase, prevents the formation of the dihydrodiols. The overall metabolism can be inhibited by the addition of alpha-naphthoflavone. The metabolism of benzo[a]pyrene in a cell culture of human scalp hair follicles has also been investigated. The results show that the activity of arylhydrocarbon hydroxylase (AHH) and epoxide hydratase (EH) is maintained in culture.
Studies of scalp-recorded brain event-related potentials in humans currently depend on the electronic averaging of many responses to the stimulus. In non-averaged single responses, it is sometimes possible to see late components such as the so-called P300, but not the shorter latency components that are much smaller and masked in background noise. We tried to identify short-latency cognitive potentials evoked by finger stimulation by comparing single trial responses that are concomitantly recorded at the contralateral and ipsilateral parietal scalp respectively. We developed a single trial topographic mapping method that proved important for assessing whether any left-right difference at short latency indeed reflected genuine cognitive electrogeneses. These results make it possible to analyze on a trial-by-trial basis the short latency cognitive processing in somatic perception.
Although microskin grafting has been used successfully to treat major burns, when the donor skin areas are inadequate, it is still not in popular use because of the difficulties of mincing and floating procedures. Floating is expected to produce more microskin patches with the dermal side upwards than with the epidermal side upwards. Another problem is that many microskin patches will be lost in the container during floating. This problem may be solved by preparing the microskin from the second layer scalp skin. This will be a graft of hair follicle cells, which can be sowed on the wound no matter which side is upwards. Grafting was carried out on well-prepared granulation beds, or on the fat surface after tangential excision, or on the bed after fascial excision of the burn. Allograft and Biobrane were used as cover dressings. The combination of fascial excision and allograft overlay gave an acceptable result. This can be an alternative method of skin grafting for burns with very limited donor skin areas when the scalp skin is not burned.
Alopecia of the unburned scalp, the temporary or permanent loss of hair, is a preventable complication. Patients at highest risk of developing alopecia are those with burn encephalopathy and in a prolonged shock state. The occipital scalp is the most common site and localized pressure-induced ischaemia is the likely cause. Frequent head repositioning and use of devices to decrease the pressure effect may decrease the incidence of this complication.
The effect on the infection rate of hair removal prior to scalp laceration repair has not been studied prospectively in the outpatient setting. Concern exists that not removing skin hair may lead to an increased incidence of serious wound infections. Sixty-eight scalp lacerations were repaired without hair removal and examined prospectively for infection. No infections were noted at 5-day follow-up. The mean patient age was 21.8 +/- 19.8 years, and the mean laceration length was 2.5 +/- 2.0 cm. The mean time from injury to repair of laceration was 2.2 +/- 2.8 hours. Sixty-three lacerations (92.7%) were repaired within 3 hours of injury. A prospective, randomized study in a select patient population to examine the effect of prior hair removal on infection rate is warranted.