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Verrucous carcinoma of the scalp.

Verrucous carcinoma is a distinctive form of low-grade squamous cell carcinoma. It typically involves the oral cavity, larynx, esophagus, and skin. Cutaneous lesions typically arise in the genitocrural area and plantar surface of the foot, with rare case reports of verrucous carcinoma arising elsewhere on the body. Human papillomaviruses, predominately types 6 and 11, have been associated with some case reports. We present a case of verrucous carcinoma arising on the scalp with negative human papillomavirus testing in a relatively young patient.

Adult↗

In vivo experimental testing and model identification of human scalp skin.

A comprehensive experimental/numerical procedure is formulated and validated for the in vivo characterization of the mechanical properties of human skin and the simulation of reconstructive surgery. The procedure uses in vivo experimental tests on undermined skin flaps, which can be performed during surgery, a numerical model formulated within the framework of nonlinear finite strain elasticity and a nonlinear parameter identification technique for the calibration of the model from indirect measurements. The procedure is applied to characterize the scalp skin tested in Raposio and Nordström (Skin Res. Technol. 4 (1998) 94). The skin is treated as a time independent, isotropic and hyperelastic membrane and the problem is solved through a finite element discretization. The study highlights that the model parameters can be determined with good accuracy using displacement measurements of a few points in the domain.

Biomechanical Phenomena↗

Time and depth resolved visualisation of the diffusion of a lipophilic dye into the hair follicle of fresh unfixed human scalp skin.

Visualising the penetration pathway of a lipophilic model dye into the hair follicle of fresh unfixed human skin would facilitate optimisation of drug formulations for local delivery to the pilosebaceous unit. A block of fresh human scalp skin was mechanically fixed in a newly designed combination of cutting device/on-line diffusion cell, manual cross-sectioned perpendicular to the skin surface and sealed to create the donor and acceptor compartment. The donor phase consisted of a saturated solution of Bodipy FL C(5) in a citric acid buffer solution. Images were obtained on-line by confocal laser scanning microscopy (CLSM) every 30 min for 16 h. For each time point and each skin region relative intensity values were calculated. The on-line visualisation showed a fast diffusion of the label into the gap of the hair follicle followed by a fluorescent staining in the gap itself. The data strongly indicate that the fluorescence in the cuticle originates mainly from the dye of the gap and not from the surrounding epidermis. The on-line visualisation provides a new and excellent tool to monitor simultaneous changes in distribution profiles in the various skin layers including the hair follicle. This information can be used to determine penetration pathways in the skin.

Aged↗

Human botfly larva in a child's scalp.

The botfly is the name for several families of hairy flies the larvae of which live as parasites in the bodies of mammals. Reported are the presentation, diagnosis, and noninvasive therapy for a botfly larva in the scalp of a 14 year old.

Adolescent↗

Paradoxical scalp lateralization of the P100 cognitive somatic potential in humans: a magnetic field study.

In somatic selective attention, electrical brain mapping disclosed a P100 cognitive electrogenesis with a scalp field paradoxically lateralized ipsilaterally to the target finger stimulus. We used 64 sensors magnetoencephalography (MEG) and source localization software in six normal humans to identify the P100 neural generator. Calculated dipole sources for P100 were iteratively compared with the recorded MEG data. The equivalent dipole at somatic P100 latency was located in the parietal lobe contralateral to the finger stimulus and had an oblique positive gradient pointing towards the ipsilateral side, thus explaining the paradoxical positivity in electrical brain mapping. It is suggested that the somatic P100 is generated in parietal area 7b which indeed appears to be specialized for cognitive processing within the somatic modality rather than for multimodal association.

Brain Mapping↗

Infantile myofibromatosis presenting with scalp dermoid cyst.

Infantile myofibromatosis is a disorder of infancy and early childhood, typically presenting as a solitary lesion or multiple widespread nodular tumors localized to skin, subcutaneous tissue, muscle, bone, viscera, or central nervous system. We present a case of infantile myofibromatosis, multicentric type, in a 4-month-old male infant who initially presented with an occipital scalp mass and other skin-colored nodular mass lesions over his face, trunk, and four limbs. He received tissue biopsy to establish a definite diagnosis. Craniotomy was also arranged for tumor removal due to dural involvement with internal extension and compression of adjacent sigmoid sinus. The patient eventually died of cardiopulmonary failure secondary to primary pulmonary hypertension at age 11 months. Before his death, he had suffered from abdominal distention and frequent vomiting, followed by aggravated respiratory distress and cyanosis. Aggressive surveillance for cardiopulmonary or gastrointestinal involvement is recommended in such cases because prognosis varies according to the involvement of vital organs.

Dermoid Cyst↗

Relative element levels in the paired samples of scalp hair and fingernails of patients from New Delhi.

Specific elements are bioconcentrated in human hair and nails, which have unique advantages of application in population monitoring studies thereby, recognized as biological tools for disease diagnosis and prevention. However, investigations are meager for relative element profile in hair and nails of same subjects. In this study, hair and nails were analyzed to find effects of age, sex, smoking habit, diet, urban and rural exposure gradients, occupation, and health on element levels. Scalp hair and fingernails were sampled along with a questionnaire from urban and rural subjects of New Delhi; patients of hypertension, coronary heart disease, and diabetes were identified clinically. Cadmium, chromium, copper, nickel, lead and zinc concentrations were determined by AAS in both the samples; CRM (human hair powder) analysis showed acceptable precision and accuracy in element measurement. In comparison to controls, Cr-H and Zn-H levels were lower respectively in female hypertensive and total hypertensive subjects, whereas, Zn-N and Cu-N were lower respectively in total CHD and diabetic subjects, and hypertensive and CHD urban subjects. Cd concentrations were higher in both the samples of tobacco smoking rural subjects than that of non-smokers. Farmers had lower Pb-H than rural businessmen did. Cr, Cu, Ni, and Zn concentrations were different due to rural and urban gradient but not to the influence of age, sex, and diet. Pb value was alone correlated between the paired samples. Thus, higher Cd levels in the smokers and lower Cr, Cu and Zn levels in the patients were observed.

Adolescent↗

Intrapartum fetal atrial bigeminy--diagnostic and therapeutic role of the fetal scalp stimulation test.

Concern for fetal hypoxia often leads to cesarean delivery when persistent fetal bradycardia is identified. A fetus with premature atrial contractions had a prolonged second-stage heart rate of 80 beats/min. Intrapartum echocardiography and electronic fetal heart rate monitoring distinguished bradycardia caused by blocked atrial bigeminy from hypoxic bradycardia. The fetal scalp stimulation test documented normal acid-base balance and normalized the ventricular rate, avoiding cesarean delivery.

Adult↗

Penetrating ocular injury with a fetal scalp monitoring spiral electrode.

PURPOSE: To report a penetrating ocular injury resulting from inadvertent placement of a fetal scalp monitoring spiral electrode into the right eye of a preterm male with a face presentation. METHODS: Case report and review of the literature. RESULTS: A spiral electrode was screwed clockwise into the right eye, tearing the inferior retina and creating two inferior iridotomies. Severe myopic astigmatism resulted from gradual lens dislocation combined with elongation of the eye. Despite persistent occlusive therapy and aggressive optical correction, before and after lensectomy at age 3 years, visual acuity was only 20/200 at age 8 years. CONCLUSIONS: Although complications from spiral monitoring electrodes are uncommon, this case emphasizes that before inserting a spiral monitoring electrode during labor, face presentation must be excluded to prevent inadvertent ocular injury.

Electrodes↗

Cutaneous capillary hemangiomas of the eyelid, scalp, and digits in premature triplets.

PURPOSE: To document the unique occurrence of multiple cutaneous capillary hemangiomas in healthy triplets. METHODS: Case reports. RESULTS: Triplets born 6 weeks prematurely were noted at birth to have classic cutaneous capillary hemangiomas that enlarged in the first few months of life. At 3 months of age, triplet #1 manifested a small capillary hemangioma on the left index finger and a large hemangioma that involved the entire left upper eyelid and completely occluded the visual axis. Triplet #2 had a small hemangioma on the thumb and a large hemangioma on the scalp of the forehead. Triplet #3 displayed only a minor hemangioma of the right upper eyelid that did not threaten her vision. The parents of the triplets admitted having a history of periocular capillary hemangioma that spontaneously resolved. Triplet #1 was managed with oral corticosteroids, with dramatic regression of the mass and exposure of the visual axis. CONCLUSIONS: Cutaneous capillary hemangioma is usually a sporadic condition. We found this tumor in premature triplets whose parents had a history of a similar tumor. This suggests that hereditary and environmental factors may play a role in the development of this tumor. We advise that medical and family histories be obtained in all children with cutaneous capillary hemangioma.

Eyelids↗

Improved reproducibility of magnetic stimulation-evoked motor potentials in the human masseter by a new method for locating stimulation sites on the scalp.

In magnetic-stimulation studies where motor-evoked potentials (MEP) are measured on different occasions, accurate relocation of the stimulation site on the scalp is essential. Here a novel method of locating neural stimulation sites was tested and the reproducibility of MEPs in the human masseter assessed. The heads of the participants were immobilized in a plastic mask that incorporated a grid overlying the left cerebral hemisphere. A figure-of-eight coil was oriented with a micromanipulator. Electrodes were placed over the right masseter using a standardized method. Two discrete sites on the grid were stimulated alternately at threshold + 10% whilst participants clenched their teeth. Recordings were repeated after the mask and electrodes had been removed and replaced. Within individual participants, the latency and amplitude of the MEP were reproducible between trials and when the mask and electrodes were replaced. The new method appears to be accurate and practical when recording longitudinal MEP data in the masseter.

Adult↗

The propagation potential. An axonal response with implications for scalp-recorded EEG.

An electrophysiological response of axons, referred to as the "propagation potential," was investigated. The propagation potential is a sustained voltage that lasts as long as an action potential propagates between two widely spaced electrodes. The sign of the potential depends on the direction of action potential propagation. The electrode towards which the action potential is propagating is positive with respect to the electrode from which it is receding. For normal frog sciatic nerves the magnitude of the propagation potential was 17% of the peak of the extracellular action potential; TEA increased it to 32%. For normal earthworm median or lateral giant fibers it was 30%. A ripple pattern on the propagation potential was attributed to variation in resistance along the length of the worm. Cooling increased the duration of the propagation potential and attenuated the higher frequency components of the ripple pattern. Differential records from two widely spaced intracellular microelectrodes in the same axon differed from the propagation potential. The amplitude of the plateau relative to the peak was smaller, it decreased as the action potential propagated from one electrode site to the other, and the potential did not return to zero as rapidly as for extracellular records. When propagation was blocked by heat, the propagation potential slowly decayed. There was no ripple pattern during the decay. In a volume conductor, electrodes contacting the worm did not show the typical propagation potential, but electrodes located a few centimeters away from the worm did. Simple core-conductor models based on classical action potential theory did not reproduce the propagation potential. More complex, modified core-conductor models were needed to accurately simulate it. The results suggest that long, slowly conducting fibers can contribute to the scalp-recorded EEG.

Animals↗

The use of selective lymphadenectomy in malignant blue naevus of the scalp.

Malignant blue naevus (MBN) is a rare cutaneous tumour with a close biological resemblance to malignant melanoma. MBN spreads to regional lymph nodes, creating a dilemma in managing patients with clinically negative nodal basins. Sentinel lymph node (SLN) biopsy has evolved as a powerful staging tool by identifying occult metastatic nodal disease in patients with cutaneous malignancies. Here, we report a patient with MBN of the occipital scalp who underwent wide local excision together with preoperative lymphoscintigraphy and intraoperative radiolymphoscintigraphy and vital dye injection to identify all draining SLNs. No occult nodal disease was identified. This report adds to the growing body of literature supporting the role of SLN biopsy in staging individuals with cutaneous malignancies, including MBN.

Adult↗

Malignant melanoma arising in a sebaceous nevus of the scalp.

This is the first report of malignant melanoma arising from sebaceous nevus (SN) of the scalp, although it has been known that various benign and malignant neoplasms may develop in association with SN. After the excisional biopsy for SN with 5 mm free margin, pathological examination revealed the coexistence of nodular melanoma invading to the reticular dermis (IV level of Clark) for a maximal depth of 4 mm. After resection with another 20 mm free margin, there has been no evidence of local recurrence or distant metastasis for nine years.

Female↗

Determination of bupivacaine in plasma by high-performance liquid chromatography. Levels after scalp infiltration in children.

The local anaesthetic bupivacaine could be very useful for analgesia in pediatric neurosurgery. Since systemic toxic reactions to bupivacaine are correlated with high plasma levels it was important, as an adjunct to clinical evaluation, to measure plasma bupivacaine. This report describes a high-performance liquid chromatography (HPLC) method for the quantitation of plasma bupivacaine. Sample preparation involves extraction into ether followed by back-extraction into HCl. After evaporation, the acid extract is redissolved and separated by reversed-phase chromatography. The assay is linear to 5 mg bupivacaine/L and shows excellent recovery and precision. With samples from children undergoing brain surgery following scalp infiltration with either 0.125% or 0.25% bupivacaine, plasma levels peak within 10 min, then fall rapidly to a plateau by 30 min. This plateau is maintained for at least 120 min. In no case did we find supposed toxic levels of bupivacaine.

Brain↗