Jacques A. Machol

Cortical plasticity induced by different degrees of peripheral nerve injuries: a rat functional magnetic resonance imaging study under 9.4 Tesla

Background Major peripheral nerve injuries not only result in local deficits but may also cause distal atrophy of target muscles or permanent loss of sensation. Likewise, these injuries have been shown to instigate long-lasting central cortical reorganization. Methods Cortical plasticity changes induced after various types of major peripheral nerve injury using an electrical stimulation technique to the rat upper extremity and functional magnetic resonance imaging (fMRI) were examined. Studies were completed out immediately after injury (acute stage) and at two weeks (subacute stage) to evaluate time affect on plasticity. Results After right-side median nerve transection, cortical representation of activation of the right-side ulnar nerve expanded intra-hemispherically into the cortical region that had been occupied by the median nerve representation After unilateral transection of both median and ulnar nerves, cortical representation of activation of the radial nerve on the same side of the body also demonstrated intra-hemispheric expansion. However, simultaneous electrical stimulation of the contralateral uninjured median and ulnar nerves resulted in a representation that had expanded both intra- and inter-hemispherically into the cortical region previously occupied by the two transected nerve representations. Conclusions After major peripheral nerve injury, an adjacent nerve, with similar function to the injured nerve, may become significantly over-activated in the cortex when stimulated. This results in intra-hemispheric cortical expansion as the only component of cortical plasticity. When all nerves responsible for a certain function are injured, the same nerves on the contralateral side of the body are affected and become significantly over-activated during a task. Both intra- and inter-hemispheric cortical expansion exist, while the latter dominates cortical plasticity.

Surgical reduction of scrotal massive localized lymphedema (MLL) in obesity

BACKGROUND Lymphedema of the penis and scrotum is physically and psychologically disabling. Obesity is a source of secondary lymphedema. When restricted to specific anatomical regions in obesity, this is termed massive localized lymphedema (MLL). Few surgical cases of specific scrotal MLL in obesity are reported in the literature. We present our case series to improve the management of this complicated pathology. METHODS This is a retrospective review of obese adult patients with clinically diagnosed scrotal MLL undergoing reduction scrotoplasty by the senior author (J.R.S.) from 1992 to 2012. Medical, social, familial, surgical, and follow-up data were extracted. Prior infection of the scrotal lymphedema, surgical details, pathologic evaluation, and postoperative complications were noted. A series of the cases is presented. RESULTS Four cases met the criteria for study. The average age was 35 years with an average body mass index of 53.9. Average resection at the first procedure was 3492 g. All patients were reconstructed with laterally based scrotal flaps. The pathology for each case was consistent with chronic lymphedema; no sarcomatous changes were noted. Fifty percent of the patients had recurrence of the scrotal MLL. The average total number of operations during the follow-up period for either complication or recurrence was two. CONCLUSIONS This is the largest case series specifically investigating surgical treatment for scrotal MLL in obesity. Lateral-based scrotal flaps (with or without mid-raphe Z-plasty) permit anatomic reconstruction. Complications are common and recurrence is frequent after surgical management. Excision with reconstruction improves urinary function and overall symptoms.

The free fillet flap after traumatic amputation: a review of literature and case report

Severe, mutilating hand injuries present difficult reconstructive scenarios. Often in these cases, portions of the amputated tissue may be used for reconstruction of the remaining digits and hand using the spare parts principle. The free fillet flap follows the spare parts concept. A literature review of free fillet flaps for hand and forearm coverage is provided. We also present a case report of a multi-digit and dorsal hand free fillet flap for coverage of a traumatic metacarpal hand. This flap demonstrates the value of ingenuity in planning during emergent trauma reconstruction.

Early evaluation of nerve regeneration after nerve injury and repair using functional connectivity MRI.

Resting state functional connectivity magnetic resonance imaging studies in rat brain show brain reorganization caused by nerve injury and repair. In this study, distinguishable differences were found in healthy, nerve transection without repair (R−) and nerve transection with repair (R+) groups in the subacute stage (2 weeks after initial injury). Only forepaw on the healthy side was used to determine seed voxel regions in this study. Disturbance of neuronal network in the primary sensory region of cortex occurs within two hours after initial injury, and the network pattern was restored in R+ group in subacute stage, while the disturbed pattern remained in R− group. These are the central findings of the study. This technique provides a novel way of detecting and monitoring the effectiveness of peripheral nerve injury treatment in the early stage and potentially offers a tool for clinicians to avoid poor clinical outcomes.

C7 nerve root sensory distribution in peripheral nerves: a bold functional magnetic resonance imaging investigation at 9.4 T.

Introduction: In this study we used a rat model to elucidate the linear make‐up of each major nerve of the upper limb by the C7 root through sensory stimulation and functional magnetic resonance imaging (fMRI). Methods: The C7 nerve root and major nerves of the right forelimb were stimulated electrically. Blood oxygen level–dependent functional magnetic resonance imaging (BOLD fMRI) was performed concurrently. Voxel overlap within the primary sensory cortex was calculated. Results: C7 comprised sensation in <1% in the musculocutaneous nerve, 6% in the ulnar nerve, 16% in the radial nerve, and 19% in the median nerve (P < 0.005 for each). The overlap was always <25% for each major nerve. Conclusions: This study helps explain why C7 is a suitable donor for brachial plexus injury treatment and why there is only a transient sensory deficit after transfer. Muscle Nerve 49: 40–46, 2014

Spindle Cell Lipoma of the Neck: Review of the Literature and Case Report.

Summary: Spindle cell lipomas (SCL) are benign, slow growing tumors arising most frequently in the subcutaneous tissue of the upper back, posterior neck, and shoulders in males aged 40–70 years. Local excision is generally curative. Classification of lipomatous tumors has progressed recently, and tumors of similar morphology and unusual presentation are increasingly reported, thereby making correct diagnosis even more vital. SCL require pathologic differentiation from liposarcoma, other spindle cell neoplasms, and myxoid lesions for treatment purposes. Cytology, histology, and cytogenetics, in conjunction with clinical presentation, are paramount in arriving at the correct diagnosis of spindle cell lipoma. We present a case report with characteristics typical of an SCL along with a literature review to further elucidate the diagnosis and surgical treatment of this soft tissue tumor.

C7 nerve root sensory distribution in peripheral nerves: A bold functional magnetic resonance imaging investigation at 9.4 T: fMRI Study of C7 Nerve Distribution

Introduction: In this study we used a rat model to elucidate the linear make‐up of each major nerve of the upper limb by the C7 root through sensory stimulation and functional magnetic resonance imaging (fMRI). Methods: The C7 nerve root and major nerves of the right forelimb were stimulated electrically. Blood oxygen level–dependent functional magnetic resonance imaging (BOLD fMRI) was performed concurrently. Voxel overlap within the primary sensory cortex was calculated. Results: C7 comprised sensation in <1% in the musculocutaneous nerve, 6% in the ulnar nerve, 16% in the radial nerve, and 19% in the median nerve (P < 0.005 for each). The overlap was always <25% for each major nerve. Conclusions: This study helps explain why C7 is a suitable donor for brachial plexus injury treatment and why there is only a transient sensory deficit after transfer. Muscle Nerve 49: 40–46, 2014

C7 Nerve Root Sensory Distribution in Peripheral Nerves: A BOLD fMRI Investigation at 9.4T

Introduction: In this study we used a rat model to elucidate the linear make‐up of each major nerve of the upper limb by the C7 root through sensory stimulation and functional magnetic resonance imaging (fMRI). Methods: The C7 nerve root and major nerves of the right forelimb were stimulated electrically. Blood oxygen level–dependent functional magnetic resonance imaging (BOLD fMRI) was performed concurrently. Voxel overlap within the primary sensory cortex was calculated. Results: C7 comprised sensation in <1% in the musculocutaneous nerve, 6% in the ulnar nerve, 16% in the radial nerve, and 19% in the median nerve (P < 0.005 for each). The overlap was always <25% for each major nerve. Conclusions: This study helps explain why C7 is a suitable donor for brachial plexus injury treatment and why there is only a transient sensory deficit after transfer. Muscle Nerve 49: 40–46, 2014