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Expansion of a large free scalp flap before transfer can allow direct closure of the flap donor site, thereby avoiding the need for a skin graft or local flap to close the donor site. A case is presented of anterior scalp reconstruction with an expanded posterior scalp free flap.
The correlation between electric source asymmetry in the brain and potential amplitude asymmetry developed on the scalp was investigated using a computerized analytical prolate spheroid model of the head. The source was modeled by a single current dipole located in the occipital region of the brain. The potential created by the dipole was calculated using Laplace's equation with boundary conditions while allowing a quasi-static formulation and linear media. The dipole was located in the inner part of a four-compartment medium representing the scalp, the skull (with non-isotropic conduction), the cerebrospinal fluid (CSF), and the cortex. The asymmetry was modeled by a dipole located with an angle to the major axis connecting the nasion and the inion. The present study shows that source asymmetry can cause non-negligible asymmetries in the potential amplitude measured on the scalp above homotopic points of the two hemispheres. A potential asymmetry of up to 15% in the O1-O2 pair of electrodes was found when the dipole is rotated from the symmetric major axis at an angle of 10 degrees. The source asymmetry in the occipital region can be related to falx deviation, which is an asymmetry present in the majority of the population. Since this asymmetry is not related to real physiologic and psychologic sources of potential amplitude asymmetries, it should be taken under consideration when potential distribution analysis is performed.
OBJECTIVES: We report the analysis of scalp topography and dipole modeling of the rolandic spikes in 6 patients suffering of benign rolandic epilepsy of childhood with extremely high amplitude SEP by tapping stimulation of the finger of the hand. METHODS: EEG and BESA analysis were performed for both rolandic spontaneous interictal spikes and high amplitude scalp activity evoked by tapping and electrical stimulation of the first finger of the right hand. RESULTS: The evoked responses showed a morphology characterized by a rapid phase (spike) followed by a slow phase (slow wave). The spike presented an early small positive component followed by a main negative component. Similar morphology, dipole configuration and source localization were observed for both rolandic spikes and evoked high amplitude scalp responses. Dipole localization showed an overlap of spatial coordinates between rolandic and evoked spikes. CONCLUSIONS: These findings suggest that the extremely high amplitude SEPs could be evoked spikes which probably had the same cortical generators of the spontaneous rolandic spikes.
Four prepubertal children, all members of melanoma-prone families, developed pigmented scalp lesions that were diagnosed as dysplastic nevi. In three cases, the scalp lesions were the only evidence that the children were affected by the dysplastic nevus syndrome, a distinctive clinicopathologic entity that identifies persons at increased risk of malignant melanoma. In general, the skin of family members with dysplastic nevus syndrome does not show characteristic lesions until just prior to or with the onset of puberty. The presence of dysplastic nevi on the scalp may permit identification of at least some high-risk family members well prior to puberty. This should facilitate the early implementation of a melanoma prevention program for susceptible individuals and help ensure that melanomas are diagnosed early in their natural history, at a time when they are surgically curable.
We have previously reported that a lipophilic yeast, Pityrosporum ovale (P. ovale) produced a high frequency of positive skin prick tests and in vitro histamine-release (HR) tests in patients suffering from atopic dermatitis (AD) of the face, scalp, and neck. In the present study, our aim was to confirm the involvement of P. ovale-specific IgE and to produce a standardized extract for diagnostic tests; 7/20 sera from patients with a positive HR test were positive in RAST. Several IgE-binding proteins could be detected with sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by immunoblotting. Comparison of different extraction methods demonstrated that allergens were not released from P. ovale until after mechanical destruction of the yeast cells. Extraction of cultured P. ovale, obtained from the skin of various individuals suffering from AD of the face, scalp, and neck, resulted in very heterogenous patterns of constituents in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting analysis. Nevertheless, all extracts were recognized by patients' IgE. P. ovale may express varying protein patterns, depending on either source or stage of differentiation. Thus, at present, skin and HR tests may be superior to other available assays for diagnosing type I reactions to P. ovale in AD of the face, neck, and scalp.
The scalp is a relatively common site of cutaneous metastasis. The usual presentation is of single or multiple firm scalp nodules. A well-recognized but rarer presentation is alopecia neoplastica that is seen as single or multiple areas of cicatricial alopecia. We describe a unique presentation of scalp metastasis in a patient with breast carcinoma in whom hair loss was clinically inconspicuous. The metastasis responded to combination chemotherapy.
Heterochromia of hair is the presence of more than one distinct color of hair in the same person. A color difference between scalp hair and a mustache or sideburns is not uncommon. Pubic and axillary hair and eyebrows and eyelashes are often darker than scalp hair in a fair-haired person. Rarely, a circumscribed patch of hair of different colors occurs. However, diffuse heterochromia of black and red scalp hair has not been previously reported. We describe a father and son with this condition.
A 23-year-old man was assaulted about the head and face with a wrench, sustaining multiple severe scalp lacerations. Massive bleeding from the lacerations ensued, resulting in refractory hypovolemic shock. Emergency department control of this hemorrhage was accomplished by the application of Raney clips to the edges of the scalp lacerations. Following stabilization and radiologic studies, the patient was admitted to the ICU, where his scalp wounds were managed definitively. The remainder of his hospital course was unremarkable, and he was discharged on the third hospital day to be followed in the surgical clinic as an outpatient.
The semi free latissimus dorsi flap is characterized by a temporary vascular anastomosis on a pedicle not belonging to the loco-regional anatomy of the skin defect; after a period of autonomy, the section of the flap pedicle is obligatory. Its advantage compared to the classic free flap is the great microsurgical security avoiding complex, and stressful supervision in the postoperative period. From June 1998 to January 2001, 7 patients ranging from 18 to 65 years old and suffering from large scalp defects going between 20 x 13 cm and 27 x 18 cm have benefited from this surgical method. The etiology of these defects was: in 4 cases dermatofibrosarcoma protuberans involving the periost, in 1 case destruction of the near entirety of the scalp and calvarium by electrical burn, in 1 case an instable scar of burn with osteomyelitis and in the last case an osteomyelitis on a frontal cranioplasty. Three stages have been used:--The thoraco-dorsal artery was anastomosed on the wrist to the radial artery in a termino-lateral way and the thoraco-dorsal vein to the superficiel radial vein in a termino-terminal way;--The flap was fixed to the forearm for 2 weeks, then, the debridement which has always exposed the dura was done; The flap was sutured to the defect after reconstruction of calvarial defect with the méthylmétacrylate implant;--After 3 weeks the pedicle was sectioned and the flap tailored exactly to the defect. No postoperative complications were reported. With a mean follow-up of 18 months, the scalp coverage was very satisfactory.
Contact heat evoked potentials (CHEPs) were collected in 12 healthy subjects by stimulating the forearm skin with a couple of thermodes at a painful intensity. The stimulated area was 628 mm(2) and the repetition rate was 0.1 Hz. The electroencephalogram was recorded by 31 electrodes placed on the scalp according to an extended 10-20 System. A dipolar model explaining the scalp CHEP distribution was built by using the brain electrical source analysis. The model includes two dipoles located bilaterally in the perisylvian region, one dipole in the deep midline region and two dipoles located bilaterally in the deep temporal lobe. This dipolar model is very similar to that previously described to explain the topography of evoked potentials to radiant heat stimulation by laser pulses. Since laser stimuli activate the nociceptive fibres, the strong similarity of the cerebral dipoles activated by contact heat stimuli and by laser pulses suggests that only nociceptive inputs are involved in the scalp painful CHEP building. Therefore, CHEP recording can be useful for clinical examination of the nociceptive system.
We compared 29 split thickness skin grafts taken from the thigh (group I) and 37 taken from the scalp (group II). The study was prospective with a follow-up period of 1 year. The average age was 29 months. Included in group I were those children whose parents refused permission for their hair to be shaved and those with burns to the head. We compared ease of technique, percentage of graft accepted, quality of the graft and after-effects of the donor site. Acceptance of the graft was close to 100 per cent in both groups. Harvesting was more difficult from the scalp (P < 0.0001). The quality of the grafts was identical in both groups. After-effects at the donor site were absent in group II and evident in group I (P < 0.0001). There was no alopecia. The scalp represented a better donor site for split-thickness skin grafting than the thigh in the child.
An atypical presentation of newborn scalp abscess is described in a 9-day-old infant. The infant appeared nontoxic upon presentation on day 9 after birth with a scalp abscess and Escherichia coli bacteremia. The infant had been admitted from the emergency department to the newborn intensive care unit on day 4 after birth with the same diagnosis; however, she was discharged within hours without treatment. This case report demonstrates the subtle clinical features, presentation, microbiology, and appropriate emergency department management of neonatal scalp abscesses.
OBJECTIVES: Being the two complementary cues to directional hearing, interaural time and intensity disparities (ITD and IID, respectively), are known to be separately encoded in the brain stem. We address the question as to whether their codes are collapsed into a single lateralization code subcortically or they reach the cortex via separate channels and are processed there in different areas. METHODS: Two continuous trains of 100/s clicks were dichotically presented. At 2 s intervals either an interaural time delay of 1ms or an interaural level difference of 20 dB (HL) was introduced for 50 ms, shifting the intracranial sound image laterally for this brief period of time. Long-latency responses to these directional stimuli, which had been tested to evoke no potentials under monotic or diotic conditions, as well as to sound pips of 50 ms duration were recorded from 124 scalp electrodes. Scalp potential and current density maps at N1 latency were obtained from thirteen normal subjects. A 4-sphere head model with bilaterally symmetrical dipoles was used for source analysis and a simplex algorithm preceded by a genetic algorithm was employed for solving the inverse problem. RESULTS: Inter- and intra-subject comparisons showed that the N1 responses evoked by IID and ITD as well as by sound pip stimuli had significantly different scalp topographies and interhemispheric dominance patterns. Significant location and orientation differences between their estimated dipole sources were also noted. CONCLUSIONS: We conclude that interaural time and intensity disparities (thus the lateral shifts of a sound image caused by these two cues) are processed in different ways and/or in different areas in auditory cortex.
OBJECTIVE: To demonstrate a novel approach for real-time and automatic detection of epileptic seizures in EEG recorded with foramen ovale (Fov) or scalp electrodes. METHODS: Our seizure detection method is based on simulated leaky integrate and fire units (LIFU), which are classical simple neuronal cell models. The LIFUs are connected to a signal preprocessing stage and increase their spiking rates in response to rhythmic and synchronous EEG signals as typically occur at the onset and during seizures. RESULTS: We analyzed 22 short-term (10+/-3 min) and 4 long-term (18+/-7 h) Fov or scalp EEGs of 10 patients with drug resistant partial epilepsy. Seizures (n=36) were marked by increases of the LIFUs spiking rates above a preset threshold. The durations of increased spiking rates due to seizures were always longer than 10 s (36+/-21 s) and allowed separation from artifacts, which caused only short durations (1.2+/-0.6 s) of high spiking rates. The LIFUs correctly detected all the seizures and produced no false alarms. In the long term Fov EEGs seizure detection occurred before the onset of clinical signs (41+/-22 s). CONCLUSIONS: By using simulated neuronal cell models it is possible to automatically detect epileptic seizures in scalp and Fov EEG with high sensitivity and specificity.
The N70 and P100 components of transient pattern visual evoked potentials (P-VEPs) were measured in migraine patients, with and without aura, and in normal subjects in order to evaluate their latency, amplitude and occipital scalp distribution. The aim was to find any typical electrophysiological abnormalities in migraine. P-VEP N70 and P100 were analyzed in 59 patients without any known visual field defect. Mean latency and amplitude values were within normal ranges for either N70 and P100 all over the occipital scalp; the only significant abnormality we found was related to the absolute right-left amplitude ratio either for N70 and P100 waves, providing an asymmetry in P-VEP scalp distribution; this finding was detected in 78.9% of patients with aura and 72.5% without aura. Our results show that in migraine patients, both P-VEP waves N70 and P100, have an asymmetric topographic distribution, even during interictal phases, that can be explained by a cortical disturbance in agreement with the neural hypothesis of headache.
A 54-year-old female presented with the cutaneous metastases of the breast carcinoma that produced combination of pigmented zosteriform eruption on the trunk and eroded plaque on the scalp, 13 years after radical mastectomy. Histologically, zosteriform lesions displayed prominent infiltration of the epidermis in nesting or linear pattern by neoplastic cells with focal formation of intraepidermal and subepidermal vesicles due to discohesion of tumor cells and dermal edema. Examination of scalp plaque revealed ulcerations and infiltration of the epidermis with scattered basal and suprabasal malignant cells in pagetoid fashion. Immunohistochemically, tumor cells were cytokeratin 7- and estrogen receptor-positive and cytokeratin 20 negative. HMB-45 and Melan-A-stained numerous dendritic melanocytes intermingled with intraepidermal and superficial dermal tumor cells in the trunk lesion, whereas on the scalp, only occasional melanocytes surrounding intraepidermal carcinomatous cells were identified. Our case described, to our knowledge, so far unreported combination of individually rare, clinical and histological patterns of cutaneous metastases from breast carcinoma in a single patient.
OBJECTIVE: The objective of this study was to determine the effect of body hair (scalp and facial) on air displacement plethysmography (BOD POD) estimates of percentage of body fat. RESEARCH METHODS AND PROCEDURES: A total of 25 men (31.4 +/- 8.0 years, 83.4 +/- 12.2 kg, 181.8 +/- 6.9 cm) agreed to grow a beard for 3 weeks to participate in the study. Total body density (g/cm(3)) and percentage of body fat were evaluated by BOD POD. To observe the effect of trapped isothermal air in body hair, BOD POD measures were performed in four conditions: criterion method (the beard was shaven and a swimcap was worn), facial hair and swimcap, facial hair and no swimcap, and no facial hair and no swimcap(.) RESULTS: The presence of only a beard (facial hair and swimcap) resulted in a significant underestimation of percentage of body fat (16.2%, 1.0618 g/cm(3)) vs. the criterion method (17.1%, 1.0597 g/cm(3), p < 0.001). The effect of scalp hair (no swim cap worn) resulted in a significant underestimation in percentage of body fat relative to the criterion method, either with facial hair (facial hair and no swimcap; 14.8%, 1.0649 g/cm(3)) or without facial hair (no facial hair and no swimcap; 14.8%, 1.0650 g/cm(3), p < 0.001 for both). DISCUSSION: A significant underestimation of percentage of body fat was observed with the presence of facial hair ( approximately 1%) and scalp hair ( approximately 2.3%). This underestimation in percentage of body fat may be caused by the effect of trapped isothermal air in body hair on body-volume estimates. Thus, excess facial hair should be kept to a minimum and a swimcap should be worn at all times to ensure accurate estimates of body fat when using the BOD POD.
Androgen exposure stimulates the growth of beard hair follicles. The follicle dermal papilla appears to be the site of androgen action; however, the molecular mechanisms that regulate this process are not well understood. In an attempt to identify genes that contribute to the androgen-responsive phenotype, we compared gene expression patterns in unstimulated and androgen-treated cultured human dermal papilla cells isolated from beard (androgen-sensitive) and occipital scalp (androgen-insensitive) hair follicles. Through this analysis, we identified three genes that are expressed at significantly higher levels in beard dermal papilla cells. One of these genes, sfrp-2 has been identified as a dermal papilla signature gene in mouse pelage follicles. Two of these genes, mn1 and atp1beta1, have not been studied in the hair follicle. A fourth, fibulin-1d, was slightly upregulated in beard dermal papilla cells. The differences in the expression of these genes in cultured beard and scalp dermal papilla cells reflected similar differences in microdissected dermal papilla isolated from intact beard and scalp follicles. Our findings introduce potentially novel signaling pathways in dermal papilla cells. In addition, this study supports that cultured dermal papilla cells provide a cell-based model system that is reflective of the biology of in vivo hair follicle cells.