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Biomedical subjects

F Forli

Publications and source records attributed to F Forli.

10 recordsLinked to original sources

Auditory neuropathy in a patient with mitochondrial myopathy and multiple mtDNA deletions.

Auditory neuropathy (AN) is a hearing disorder characterized by the absence or severe distortion of the auditory brainstem responses, in the presence of preserved otoacoustic emissions. This peculiar combination suggests the presence of a defect impinging upon the functional complex formed by inner hair cells, the primary afferents (spiral ganglion neurones) and the first order synapses between hair cells and the cochlear nerve. Typically, AN patients show a severe speech perception impairment, which appears reduced out of proportion to pure tone threshold, but the clinical presentation of AN is quite complex. Hearing loss is a common symptom associated with mitochondrial diseases; however, AN has only rarely been reported in these disorders. Here we report a rare association, the first case observed in Italy, in a patient with autosomal recessive mitochondrial myopathy and mitochondrial DNA multiple deletions, and a hearing deficit with the audiological and electrophysiological features of AN.

DNA, Mitochondrial↗

Mutations in the SLC26A4 (pendrin) gene in patients with sensorineural deafness and enlarged vestibular aqueduct.

Pendred syndrome and the enlarged vestibular aqueduct (EVA) are considered phenotypic variations of the same entity due to mutations in the SLC26A4 (pendrin) gene. Pendred syndrome consists in sensorineural deafness, goiter and impaired thyroid hormone synthesis while in EVA thyroid function seems to be preserved. The aim of this study was to evaluate thyroid function and morphology and to look for mutations in the SLC26A4 gene in patients presented with EVA. Among 57 consecutive patients with sensorineural deafness 15 with EVA, as assessed by magnetic resonance imaging (MRI), were identified and studied. A complete evaluation of thyroid function including thyroid echography and perchlorate discharge test was carried out in all patients with EVA; all exons of the SLC26A4 gene were amplified from peripheral leukocytes and directly sequenced, using specific intronic primers. Out of 15 patients with EVA, goiter was present in 8 (53%), hypothyroidism in 7 (47%), increased serum thyroglobulin levels in 8 (53%) and a positive perchlorate discharge test in 10 (67%). Nine alleles of the SLC26A4 gene were mutated: 2 novel mutations (L465W and G497R) and 4 already known mutations (T410M, R409H, T505N and IVS1001+1G>A) were found. Four subjects were compound heterozygous and 1 heterozygous (G497R/wt). All patients harbouring mutations in the SLC26A4 gene had goiter and a positive perchlorate discharge test: 3 were slightly hypothyroid and 2 euthyroid. The remaining 10 patients had no mutations in the SLC26A4 gene: 4 of them were hypothyroid, 2 with goiter and positive perchlorate discharge test, 2 without goiter and with negative perchlorate discharge test. Two patients without mutations were euthyroid with positive perchlorate discharge test. Patients with mutations in the SLC26A4 gene had larger thyroid volume (p<0.002), higher serum thyroglobulin (Tg) levels (p<0.002) and greater radioiodine discharge after perchlorate (p=0.09) than patients without mutations. The results of the present study lend support to the concept that all patients with mutated SLC26A4 gene have abnormalities of thyroid function tests.

Adolescent↗

A non-syndromic hearing loss caused by very low levels of the mtDNA A3243G mutation.

We described a patient with progressive non-syndromic hearing loss (NSHL) harboring the A3243G mutation in the mitochondrial DNA (mtDNA). Muscle biopsy showed scattered ragged-red, cytochrome c oxidase negative fibers, whereas the biochemical analysis of the mitochondrial respiratory chain complexes was normal. Restriction fragment length polymorphism (RFLP) analysis showed A3243G mtDNA transition, present at very low in patient's muscle (3%) and in urinary sediments (1%), and not detectable in blood and buccal mucosa. The patient was submitted to a bilateral cochlear implantation with post-operative excellent hearing and communicative outcomes. Our findings indicate that A3243G mutation may be responsible both for SHL and NSHL, may be depending on the levels of mutated mtDNA. Patients with hearing loss due to mtDNA mutations should be considered as good candidates for cochlear implantation.

Aged↗

Virtual endoscopy of the middle ear.

Virtual endoscopy is a computer-generated simulation of fiberoptic endoscopy, and its application to the study of the middle ear has been recently proposed. The need to represent the middle ear anatomy by means of virtual endoscopy arose from the increased interest of otolarygologists in transtympanic endoscopy. In fact, this imaging method allows the visualization of middle ear anatomy with high detail, but it is evasive and is essentially used for surgical guidance. Virtual endoscopy provides similar perspectives of the tympanic cavity but does not require the tympanic perforation. In the study of the middle ear, specific attention is given to the retroperitoneum. This region contains elevations of the medial wall (pyramidal eminence and ridge, styloid eminence and ridge, subiculum, ponticulus) and depressions (sinus tympani, posterior sinus tympani, facial sinus, fossula of Grivot, oval window fossula), which can be effectively displayed by virtual endoscopy. Virtual endoscopy is foreseen as a useful tool in preoperative management of patients who are candidates for middle ear surgery, since it can predict with high detail the patient's specific anatomy by imaging perspectives familiar to otosurgeons.

Computer Simulation↗

Large vestibular aqueduct in distal renal tubular acidosis. High-resolution MR in three cases.

High-resolution MR of the inner ear performed in 3 consecutive pediatric patients affected by distal renal tubular acidosis (dRTA) and progressive sensorineural hearing loss (SNHL) revealed enlarged vestibular aqueducts (LVA) (bilateral in 1 case and unilateral in 2). LVA is associated to sporadic, progressive SNHL, often secondary to minor head trauma and activities involving the Valsalva maneuver. We believe that the presence of LVA may have contributed to the onset of SNHL and its progression in our patients, and therefore want to stress the importance of morphological studies of the inner ear in patients affected by dRTA and SNHL.

Acidosis, Renal Tubular↗

Sudden bilateral hearing loss and sporadic mitochondrial DNA deletion.

Several studies have indicated that a number of different mitochondrial DNA (mtDNA) mutations may be responsible for human pathologies. Sensorineural Hearing Loss (SNHL) may be associated with known syndromes (syndromal SNHL) or represent the only manifestation of mitochondrial damage (non-syndromal hearing loss). Moreover, mtDNA alterations may be responsible for aminoglycoside-induced deafness. We describe a patient harbouring a single sporadic mtDNA deletion, who presented with sudden adult-onset bilateral, although non-simultaneous SNHL, that was partially responsive to corticosteroids. Increased values of rest, and exercise, blood lactic acid were decisive for diagnosis, prompting muscle biopsy that revealed the mtDNA deletion. The case underscores the importance of investigating a mitochondrial disease in cases of SNHL of unknown origin and points out the importance of an increased blood level of lactic acid as a screening test.

DNA, Mitochondrial↗

Langerhans' cells histiocytosis.

Langerhans cell histiocytosis (LCH) is a rare disorder of unknown cause, characterized by the proliferation of histiocytic cells in various tissues and organs. The role of the otolaryngologist is important in the early and accurate evaluation, staging and diagnosis of LCH, because it may mimic more common diseases such as otitis externa and acute mastoiditis. We discuss a case report of bilateral mastoid involvement in a child with a history of otalgia unresponsive to medical therapy.

Acute Disease↗

[Orbital decompression in Grave's disease: comparison of techniques].

Grave's ophthalmopathy is an inflammatory, autoimmune disorder often associated with Grave's disease. The inflammatory infiltration involves the retrobulbar fatty tissue and the extrinsic eye muscles, causing proptosis, extraocular muscle dysfunction and often diplopia. Orbital decompression is an effective treatment in such cases, particularly when resistant to drugs and external radiation therapy. This work compares the results of orbital decompression performed by removing: a) the medial and lateral walls (Mourits technique) in 10 patients (19 orbits) and b) the medial and lower walls (Walsh-Ogura technique) in 17 patients (31 orbits). The results show that removing the floor of the orbit enables better reduction of proptosis but more easily leads to post-operative diplopia. Thus it proves necessary to combine the two techniques, modifying the surgical approach on a case-by-case basis.

Decompression, Surgical↗

[Diagnostic and therapeutic approach to progressive sensorineural hearing loss].

Progressive sensorineural hearing loss (PSNHL) is an important clinical entity that can develop rapidly and evolve to deafness. The causes of PSNHL can be divided into hereditary, developmental, infectious, autoimmune, metabolic, vascular, neoplastic, toxic and degenerative, even if the origin of the hearing impairment often remains unknown and a diagnosis of idiopathic PSNHL is made. In order to establish the etiology of the hypoacusia or to rule out any known etiology of PSNHL and to diagnose an idiopathic form, a detailed family, physiological and medical history has to be obtained, including history of pregnancies. A careful audiological and otoneurological evaluation should also be carried out, followed by laboratory tests. Furthermore, a complete otoneurological evaluation is required, with puretone audiometry, speech audiometry, impedance audiometry and study of the stapedial reflex, brainstem auditory evoked potentials and vestibular examination. Finally, patients with PSNHL must undergo neuroradiological examination (computerized tomography of petrosal bone, cerebral magnetic resonance and inner ear magnetic resonance); ophthalmological, rheumatological and neuropsychiatric (in childhood) advices should be sought, while other advices may be required on the basis of a particular clinical suspicion. When the etiology is established, therapy must be based on specific treatment for the cause of the hearing deficit; for example, hormonal therapy in alterations of thyroid function, antibiotic treatment in bacterial infections, calcium-antagonist and antiaggregant drugs in the vascular forms, corticosteroids or cyclophosphamide or other immunosuppressive drugs in PSNHL associated with systemic autoimmune diseases. In idiopathic hearing loss, treatment must be started in the absence of important contraindications. The therapeutic protocol that we use in such cases is the following: methylprednisolone boluses, 500 mg/day for three consecutive days, and subsequently oral treatment gradually tapering off in association with a cycle of hyperbaric therapy. Patients showing clinical and historical indications are also treated with intravenous glicerolo, calciparina and/or antiaggregant and calcium-antagonist drugs.

Clinical Protocols↗