Additional vascular compression of the brachial plexus in a cadaver with a cervical rib: case illustration.

Cervical ribs are uncommon and occur in approximately 0.5-1% of the population. The authors describe a cadaver found to have a cervical rib with further compression by the dorsal scapular artery. This vessel originated from the third portion of the subclavian artery. No other anomalies were found in this specimen. The authors speculate that some cases of symptomatic cervical rib may have an additional vector of compression from a dorsal scapular artery when it arises from the third portion of the subclavian artery. Additional studies aimed at the vascular system may be useful in diagnosis and operative planning for symptomatic patients.

Dysfunctional cilia lead to altered ependyma and choroid plexus function, and result in the formation of hydrocephalus.

Cilia are complex organelles involved in sensory perception and fluid or cell movement. They are constructed through a highly conserved process called intraflagellar transport (IFT). Mutations in IFT genes, such as Tg737, result in severe developmental defects and disease. In the case of the Tg737orpk mutants, these pathological alterations include cystic kidney disease, biliary and pancreatic duct abnormalities, skeletal patterning defects, and hydrocephalus. Here, we explore the connection between cilia dysfunction and the development of hydrocephalus by using the Tg737orpk mutants. Our analysis indicates that cilia on cells of the brain ventricles of Tg737orpk mutant mice are severely malformed. On the ependymal cells, these defects lead to disorganized beating and impaired cerebrospinal fluid (CSF) movement. However, the loss of the cilia beat and CSF flow is not the initiating factor, as the pathology is present prior to the development of motile cilia on these cells and CSF flow is not impaired at early stages of the disease. Rather, our results suggest that loss of cilia leads to altered function of the choroid plexus epithelium, as evidenced by elevated intracellular cAMP levels and increased chloride concentration in the CSF. These data suggest that cilia function is necessary for regulating ion transport and CSF production, as well as for CSF flow through the ventricles.

Novel surgical approach to the carpal tunnel: cadaveric feasibility study.

Carpal tunnel syndrome is the most common entrapment neuropathy dealt with by the clinician. Multiple techniques have been used to surgically treat this pathological condition and all of these approach the carpal tunnel from the palmar surface of the hand or wrist. We have developed a novel endoscopic approach to the carpal tunnel utilizing a dorsal approach that necessitates a good appreciation of the anatomy of this region. This approach was carried out in 10 hands. Through a single dorsal incision we were able to transect the flexor retinaculum in all specimens without obvious damage to neural or vascular tissues. The microscissors used in our study were found to be too delicate for transection of the flexor retinaculum thus another cutting tool should be considered. Our dorsal approach with visualization of the internal aspect of the flexor retinaculum may obviate many of the complications that are seen with the current techniques used to surgically treat carpal tunnel syndrome such as injury to the median nerve and its branches. Clinical trials are now necessary with prospective randomized studies that will determine which techniques are most efficacious and minimize complications most effectively.

Landmarks for the greater petrosal nerve.

The anatomy of the greater petrosal nerve while within the middle cranial fossa is lacking in the English literature and must be well understood by the surgeon who operates in this area. Twenty-two sides from six female and five male cadavers were examined. Measurements were made between the greater petrosal nerve as it coursed through the middle cranial fossa and surrounding structures such as the arcuate eminence and lateral wall of the middle cranial fossa. Mean distances from the arcuate eminence to the hiatus of the greater petrosal nerve into the middle cranial fossa measured 17.5 mm (SD = 2.2). The length of this nerve within the middle fossa was approximately 10 mm (SD = 2). From the lateral wall of the middle fossa to a midpoint of the greater petrosal nerve mean distances measured 39 mm (SD = 2.4). The mean distance from the foramen spinosum to the exit of this nerve inferior to the trigeminal ganglion measured 7 mm (SD = 1.8). These measurements will hopefully aid the surgeon who wishes to expose or avoid the greater petrosal nerve within the middle cranial fossa.

Accessory obturator nerves with bilateral pseudoganglia in man.

During the routine dissection of the pelvis and anterior thigh of an adult female cadaver, accessory obturator nerves were found bilaterally with pseudoganglia. In addition, each accessory obturator nerve rejoined the anterior division of the normally placed obturator nerves after traveling superficial to the pubic bones. Histological sections revealed primarily normal nerve with no neuronal cell bodies within these focal areas of enlargement. No inflammatory response was noted in these histologically normal peripheral nerve structures. Further gross anatomy including other peripheral nerves was found to be normal. Peripheral nerve "ganglia" are found in the literature with little focus on histology. Our case report represents to our knowledge, the first report of a pseudoganglion in association with an accessory obturator nerve.