Search Results

You are looking at 1 - 10 of 59 items for

  • Author or Editor: Mohammadali M. Shoja x
Clear All Modify Search
Restricted access

Mohammadali M. Shoja and Joshua J. Chern

Restricted access

R. Shane Tubbs, Joshua M. Beckman, Marios Loukas, Mohammadali M. Shoja and Aaron A. Cohen-Gadol

Object

Various donor nerves have been used for brachial plexus neurotization procedures. To the authors' knowledge, neurotization of median nerve branches to the pronator teres to the radial nerve at the elbow have not been explored.

Methods

In an attempt to identify an additional nerve donor candidate for neurotization procedures of the upper limb, 20 cadaveric upper limbs underwent dissection of the cubital fossa and identification of branches of the median nerve to the pronator teres. Measurements were made of such branches, and distal transection was then performed to determine the appropriate length so that the structure could be brought to the laterally positioned radial nerve via tunneling deep to the biceps brachii muscle.

Results

All specimens were found to have a median nerve branch to the pronator teres that was long enough to reach the radial nerve in the cubital fossa. Neural connections remained tension free with full pronation and supination. The mean length of these branches to the pronator teres was 3.6 cm. The overall mean diameter of these nerves was 1.5 mm. The mean proximal, midpoint, and distal diameters were 2.0, 1.8, and 1.5 mm, respectively. The mean distance between the origin of these branches to the pronator teres and the medial epicondyle of the humerus was 4.1 cm.

Conclusions

Based on the results of our cadaveric study, the use of the branch of the median nerve to the pronator teres muscle may be considered for neurotization of the radial nerve in the cubital fossa.

Restricted access

R. Shane Tubbs, Martin M. Mortazavi, Mohammadali M. Shoja, Marios Loukas and Aaron A. Cohen-Gadol

Object

Additional nerve transfer options are important to the peripheral nerve surgeon to maximize patient outcomes following nerve injuries. Potential regional donors may also be injured or involved in the primary disease. Therefore, potential contralateral donor nerves would be desirable. To the authors' knowledge, use of the contralateral spinal accessory nerve (SAN) has not been explored for ipsilateral neurotization procedures. In the current study, therefore, the authors aimed to evaluate the SAN as a potential donor nerve for contralateral nerve injuries by using a novel technique.

Methods

In 10 cadavers, the SAN was harvested using a posterior approach, and tunneled subcutaneously to the contralateral side for neurotization to various branches of the brachial plexus. Measurements were made of the SAN available for transfer and of its diameter.

Results

The authors found an SAN length of approximately 20 cm (from transition of upper and middle fibers of the trapezius muscle to approximately 2–4 cm superior to the insertion of the trapezius muscle onto the spinous process of T-12) available for nerve transposition. The average diameter was 2.5 mm.

Conclusions

Based on these findings, the contralateral SAN may be considered for ipsilateral neurotization to the suprascapular and axillary nerves.

Restricted access

R. Shane Tubbs, Martin M. Mortazavi, Marios Loukas, Mohammadali M. Shoja and Aaron A. Cohen-Gadol

Object

Knowledge of the detailed anatomy of the craniocervical junction is important to neurosurgeons. To the authors' knowledge, no study has addressed the detailed anatomy of the intracranial (first) denticulate ligament and its intracranial course and relationships.

Methods

In 10 embalmed and 5 unembalmed adult cadavers, the authors performed posterior dissection of the craniocervical junction to expose the intracranial denticulate ligament. Rotation of the spinomedullary junction was documented before and after transection of unilateral ligaments.

Results

The first denticulate ligament was found on all but one left side and attached to the dura of the marginal sinus superior to the vertebral artery as it pierced the dura mater. The ligament always traveled between the vertebral artery and spinal accessory nerve. On 20% of sides, it also attached to the intracranial vertebral artery and, histologically, blended with its adventitia. In general, this ligament tended to be thicker laterally and was often cribriform in nature medially. The hypoglossal nerve was always superior to the ligament, which always concealed the ventral roots of the C-1 spinal nerve. The posterior spinal artery traveled posterior to this ligament on 93% of sides. On one left side, the ascending branch of the posterior spinal artery traveled anterior to the ligament and the descending branch traveled posterior to it. Following unilateral transection of the intracranial denticulate ligament, rotation of the spinomedullary junction was increased by approximately 25%.

Conclusions

Knowledge of the relationships of the first denticulate ligament may prove useful to the neurosurgeon during procedures at the craniocervical junction.

Restricted access

R. Shane Tubbs, Martin M. Mortazavi, Marios Loukas, Mohammadali M. Shoja and Aaron A. Cohen-Gadol

Object

Knowledge of the variations in the nerves of the posterior cranial fossa may be important during skull base approaches. To the authors' knowledge, intracranial neural interconnections between the glossopharyngeal and vagus nerves have not been previously investigated.

Methods

The senior author (A.C.G.) noted the presence of an intracranial interneural connection between the glossopharyngeal and vagus nerves during microvascular decompression surgery in a patient suffering from hemifacial spasm. To further investigate the approximate incidence and significance of such an interneural connection, the authors studied 40 adult human cadavers (80 sides) and prospectively evaluated 16 additional patients during microvascular procedures of the posterior cranial fossa.

Results

In the cadavers, the incidence of intracranial neural connections between the glossopharyngeal and vagus nerves was 2.5%. The only such connection found in our series of living patients was in the patient in whom the connection was initially identified. These interconnections were more common on the left side. Based on our findings, we classified these neural connections as Types I and II. In the cadavers, the length and width of this connection were approximately 9 mm and 1 mm, respectively. Histological analysis of these connections verified their neural content.

Conclusions

Although these connections are rare and the significance is unknown, knowledge of them may prove useful to surgeons who operate in the posterior fossa region so that they may avoid inadvertent traction or transection of these interconnections. Additionally, such connections might be considered in patients with recalcitrant neuralgia after microvascular decompression and rhizotomy of the glossopharyngeal nerve.

Restricted access

R. Shane Tubbs, Mark Hill, Marios Loukas, Mohammadali M. Shoja and W. Jerry Oakes

Object

Many authors have concluded that the Chiari malformation Type I (CM-I) is due to a smaller than normal posterior cranial fossa. In order to establish this smaller geometry as the cause of hindbrain herniation in a family, the authors of this paper performed volumetric analysis in a family found to have this malformation documented in 4 generations.

Methods

Members from this family found to have a CM-I by imaging underwent volumetric analysis of their posterior cranial fossa using the Cavalieri method.

Results

No member of this family found to have CM-I on preoperative imaging had a posterior fossa that was significantly smaller than that of age-matched controls.

Conclusions

The results of this study demonstrate that not all patients with a CM-I will have a reduced posterior cranial fossa volume. Although the mechanism for the development of hindbrain herniation in this cohort is unknown, this manifestation can be seen in multiple generations of a familial aggregation with normal posterior fossa capacity.

Restricted access

R. Shane Tubbs, Joseph Miller, Marios Loukas, Mohammadali M. Shoja, Ghaffar Shokouhi and Aaron A. Cohen-Gadol

Object

The perineal branch of the posterior femoral cutaneous nerve (PBPFCN) has received little attention in the literature. Because perineal pain syndromes can be disabling and pudendal nerve surgical decompression/block is often not efficacious, an anatomical study of this cutaneous nerve of the perineum seemed warranted.

Methods

The authors dissected 20 adult cadavers (40 sides) to identify the branching pattern and landmarks for the PBPFCN.

Results

This branch arose directly from the posterior femoral cutaneous nerve in 55% of sides and from the inferior cluneal nerve in 30% of sides. It was absent in 15% of sides. On average, the nerve coursed 4 cm inferior to the termination of the sacrotuberous ligament onto the ischial tuberosity. No PBPFCN was found to pierce the sacrotuberous ligament. The PBPFCN provided 2–3 branches to the medial thigh that continued on to the scrotum and labia major. In general, 2 small ascending branches were identified. In males, one ascending branch traveled inferior to the corpora cavernosum and anterior to the spermatic cord to cross the midline. The other ascending branch traveled to skin at the junction of the perineum and adductor tendon. A single descending branch, approximately 2 mm in diameter, traveled to the inferior scrotum anterior to the testicle in the male specimens and the lower labia majora in the female specimens. Communications between the PBPFCN and the perineal branch of the pudendal nerve were common.

Conclusions

Entrapment of the PBPFCN may be the cause of some forms of the perineal pain syndrome. Specific knowledge of the PBPFCN may assist surgeons in releasing and anesthetizing this cutaneous nerve of the perineum.

Restricted access

R. Shane Tubbs, Marios Loukas, Mohammadali M. Shoja and Aaron A. Cohen-Gadol

Object

Emergency access to the ventricular system is sometimes necessary for the treatment of raised intracranial pressure with ensuing herniation. One procedure described in the literature is a transorbital approach performed using a spinal needle. Because past publications have been case reports with minimal definition of external landmarks, the present study was performed.

Methods

Five adult cadavers (10 sides) underwent transorbital puncture of the lateral ventricles. This approach was performed following an axial section through the cranium that exposed the lateral ventricular system. Landmarks for the ideal placement of catheters into the ventricular system were then evaluated.

Results

The authors found that the lateral ventricular system was consistently entered just superior to the level of the foramen of Monro by puncturing the roof of the orbit just medial to a midpupillary line, with the trajectory of the perforation aimed 45° from a horizontal line and 15–20° medial to a vertical line.

Conclusions

Although it is uncommon, transorbital ventriculostomy may be used in emergency cases of raised intracranial pressure. Such refined landmarks as described in the present study may be of use to the neurosurgeon.

Restricted access

R. Shane Tubbs, Mohammadali M. Shoja, Marios Loukas, W. Jerry Oakes and Aaron Cohen-Gadol

William Henry Battle (1855–1936) practiced medicine in England > 1 century ago and is primarily remembered for his description of ecchymosis over the mastoid, which indicates fracture of the skull base. Although Mr. Battle made many contributions to medicine, almost nothing exists in the literature regarding his life and findings, especially in regard to head injury. The following is a review of Battle's background and his contributions to medicine, specifically his observations associated with basilar skull fractures.

Restricted access

R. Shane Tubbs, Marios Loukas, Mohammadali M. Shoja and Aaron A. Cohen-Gadol

Description of and treatment for trigeminal neuralgia has a long history. One pivotal pioneer in this disease, however, has been more or less lost to history, along with his first description of a series of patients treated successfully for trigeminal neuralgia with surgery. John Murray Carnochan, a surgeon practicing in New York City, performed successful neurosurgery on 3 patients some 3 decades earlier than the first commonly accepted successful procedure by William Rose of London in 1890. In the present paper, the authors discuss the life of Dr. Carnochan and his descriptions of patients with trigeminal neuralgia. Based on this review, John Murray Carnochan should properly be remembered as the first surgeon to perform successful neurosurgery for trigeminal neuralgia.