Arun K. Gadre

Middle fossa decompression of the internal auditory canal in acoustic neuroma surgery: A therapeutic alternative

Unilateral acoustic neuromas in only‐hearing ears and bilateral acoustic neuromas (NF‐2) are separate entities, but both pose a common problem because surgical removal has the potential to leave the patient totally deafened.

A Scanning Electron Microscope Study of the Human Cervical Lymph Node

Arterial casts of human cervical lymph nodes were studied using scanning electron microscopy. Human cervical lymph nodes appear to be much more complex and dense than their animal counterparts. Human lymph nodes have a separate medulla arising from the hilar artery complex and cortical structure derived from capillaries. Also present is a previously unknown rosette formation of blood vessels. The possible implications of these findings for inflammatory and neoplastic diseases are discussed.

VENOUS CHANNELS OF THE PETROUS APEX : THEIR PRESENCE AND CLINICAL IMPORTANCE

A methyl methacrylate casting technique was used to make detailed casts of the intracerebral venous system of four human cadaver specimens. Seven of the eight petrous apices studied were diploeic (n = 5), or pneumatic (n = 2) and had venules coursing in the anterior petrous apex. These venules form conduits connecting the cavernous to the inferior petrosal sinus or the jugular bulb and have not been previously described. In addition to the air cell system of the petrous apex, these venules may represent pathways for the spread of infection and the development of petrous apicitis, Gradenigos syndrome, and the rare otogenic cavernous sinus thrombophlebitis. Their presence also may help explain the location of cholesterol granulomas, which afflict this area of the skull base.

Chondrogenic potential of tragal perichondrium: A cause of hearing loss following stapedectomy

Tragal perichondrium is a widely used tissue seal in the oval window following stapes surgery. Autogenous and easily accessible, it is a suitable substance to cover the vestibule in total stapedectomy, and to seal around the prosthesis in small‐fenestra stapedotomy. The incidence of complications from the use of perichondrium in this manner is exceedingly low.

Ultrastructural characterization of otospongiotic lesions in re-embedded celloidin sections

A technique of using re-embedded celloidin sections for ultrastructural analysis was used for the study of otospongiosis in human temporal bones. Celloidin sections stored in 80% alcohol with active lesions of cochlear otospongiosis were processed and re-embedded in epoxy resin. Semithin and thin sections were cut and analysed for a characterization of the ultrastructural cellular histopathology. The predominant cell types were found to be osteoblasts/osteocytes and macrophages. Lymphocytes were also noted but were rare. Several osteoblasts showed signs of active collagen and bone matrix production, indicative of ongoing new bone formation and repair. Macrophages often interacted physically to form cell clusters. The macrophages were frequently observed to endocytose the non-mineralized bone matrix as well as to degrade mononuclear cells presumed to represent osteoblasts. The observations may support the notion that increased osteolysis in active ostospongiosis is partly caused by a recruited osteoclast activity and partly by an impaired bone repair mechanism due to a macrophage digestion of osteoblast-deposited non-mineralized bone matrix. These two conditions may act in concert with cellular degradation of bone-producing cells.

Fibrous Dysplasia of the Temporal Bone: Imaging Characteristics and Neurotologic Considerations

Introduction: Fibrous dysplasia (FD) is a progressive, often indolent bone disorder in which normal bone marrow is replaced by a mixture of fibrous tissue and woven bone. It can potentially involve the long bones, pelvis, and craniofacial bones, either as monostotic or polyostotic disease. FD of the skull most commonly involves the frontal and sphenoid bones. Isolated FD of the temporal bone is relatively rare. Case Report: A 15-year-old boy presented with several weeks of progressive left-sided headaches. He was neurologically intact including facial nerve, hearing, and vestibular examinations. Imaging revealed an extradural left middle fossa lesion appearing to arise from the bones of the inner ear. Temporal bone CT demonstrated that the lesion abutted the geniculate ganglion, the labyrinthine and tympanic segments of CN VII, the superior semicircular canal, and the petrous carotid. The patient was taken to surgery, where radical resection was limited by proximity to the facial nerve, which was adjacent to the field but not compressed. The diagnosis of FD was confirmed by pathology. Postoperatively, the patient developed a delayed House-Brackmann 3 facial droop which was self-limited. Discussion: The etiology of FD is a somatic missense mutation in the gene GNAS1, which encodes the alpha subunit of the stimulatory G protein-coupled receptor Gsα. The mutation leads to constitutive, ligand-independent activation and accumulation of cAMP, similar to the effect of continuous parathyroid hormone stimulation. Studies of the natural history of FD have suggested that the disease becomes inactive after puberty, although as many as one third of patients have recurrence in adulthood. Postpubertal disease progression is observed more commonly in the polyostotic rather than the monostotic disease variant. The incidence of malignant transformation is reported at 0.4%, although sarcomatous transformation has been strongly associated with radiation treatment. Radiologically, three patterns of FD have been described: pagetoid (ground-glass), the most common; sclerotic; and cystic, the least common (10% of cases) and of which the present case is an example. Retroauricular swelling and hearing disturbances are the most common presenting complaints in patients with temporal bone FD. A recent temporal bone FD case series reported eight of nine patients presenting with conductive or sensorineural hearing loss. Radical excision is generally recommended when technically and cosmetically feasible to minimize the risk of disease recurrence. Recurrence rates of 25% have been reported for subtotal resection. Conclusions: Temporal bone fibrous dysplasia can involve the vestibular apparatus, organs of hearing, and the cranial nerve VII-VIII complex. Delayed facial nerve palsy after decompression can have a favorable prognosis. Radical resection may not be necessary for a good outcome.

New etiology for external auditory canal stenosis: sarcoidosis

algorithm of communication between patient and doctor, which includes checks for the state of communication density. The questions consider the social situation of the patient, choices of different medical treatments, and ethics, religious, and economic points of view concerning disease. An intermediate state of the patient’s communicative skill is defined in three groups, which needs recursive information transfer between patient and doctor, before the final decision can be made by informed consent.