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T Ferrer

Publications and source records attributed to T Ferrer.

26 records · Page 2Linked to original sources
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[Neurophysiological study of thin myelinated and unmyelinated fibers].

INTRODUCTION: Standard neurophysiological techniques evaluate thick myelinated fibers. Yet, peripheral nerves are equally composed of thin myelinated and unmyelinated fibers. The latter are responsible for autonomic function as well as temperature and pain perception. DEVELOPMENT: Microneurographic studies are restricted to investigation laboratories. Since the techniques are complex and invasive, their performance is still poor for clinical purposes and some of the components to be analyzed, such as cardiovagal, cannot be directly recorded. The clinical need to evaluate the functions regulated by the autonomic nervous system (ANS) had led to devising a series of tests which, in most cases, rely on reflex responses evoked by already known standardize stimuli. The battery chosen has to be non invasive, reproducible, specific, providing relevant data to the investigated function, with a readily available technology, which has to be managed being aware of the physiological and pathological factors that might bear an influence on the results. The recent development of heart rate and blood pressure power spectral analysis, provides a new interesting insight for quantification of ANS abnormalities. The study of thermography and thermometry of body surface brings forward evidence on the activity of other thin and unmyelinated fibers components of the peripheral nerve spectrum. CONCLUSION: The adequate management of the above mentioned tests gives rise to a more extensive and appropriate knowledge of the whole peripheral nerve fiber spectrum.

Arrhythmias, Cardiac↗
PubMedDate not supplied

[Small fiber dysfunction in peripheral neuropathies].

INTRODUCTION: Disfunction of thin myelinated and unmyelinated fibers may appear isolated or in association with large-myelinated fibers lesion. Small-fiber neuropathy includes autonomic and sensory symptoms, most prominent of them thermo-algesic deficits. DEVELOPMENT AND CONCLUSION: In some acute neuropathies, small-fiber lesion is relatively pure, as in pandysautonomia, but it also appears in disorders with prominent somatic involvement, such as the Guillain-Barre syndrome, in which case autonomic symptoms worsens the prognosis. Small-fiber dysfunction is important in certain diseases that involve different components of the nervous system, like paraneoplastic syndromes and porphyria. Some drugs and toxic substances may damage thin myelinated and unmyelinated fibers. Nowadays, chronic idiopathic small-fiber neuropathy is diagnosed more frequently, because of the recent development of techniques that selectively evaluate this peripheral nerve component. Hereditary sensory and autonomic neuropathies can also be studied. Small-fiber dysfunction is very prominent in some diseases, e.g. diabetes mellitus and amyloidosis. In the pure autonomic failure, only the peripheral component of the autonomic nervous system is affected, and this feature is the key to make diagnosis versus multisystem atrophy. There are situations in which there is no clear deviation from normality, namely old age autonomic failure and orthostatic intolerance syndrome in which autonomic evaluation is mandatory.

Acute Disease↗
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Multimodal evoked potentials in multiple system and late onset cerebellar atrophies.

Forty subjects were clinically examined using scales for cerebellar, pyramidal, parkinsonian, and mental status and by quantitative evaluation of neuroimages. The patients were classified into two groups: cerebellar-plus and "pure" cerebellar syndromes. Patients with "pure" cerebellar syndrome were diagnosed as autosomal dominant cerebellar ataxia III (ADCA III) or "pure idiopathic" late-onset cerebellar ataxia (ILOCA) in this series. Patients with cerebellar-plus syndrome were diagnosed as multiple system atrophy (MSA), subclassified as either ILOCA-plus, ADCA I, ADCA II or autosomal recessive LOCA. We have used visual (VEP), brainstem auditory (BAEP) and somatosensory (SEP) evoked potentials in order to establish their diagnostic validity. Cerebellar-plus syndrome and "pure" cerebellar syndrome showed overlapping VEP, BAEP and SEP abnormalities. VEP P100 latency, however, shows a certain ability to differentiate between the two groups (p = 0.08) and appears useful in distinguishing between sporadic cerebellar-plus syndromes (MSA or ILOCA-plus) and "pure" cerebellar syndromes (p < 0.02). The incidence of prolonged N9-N13 latency was significantly higher in the latter subgroup (p < 0.04) as well. Within cerebellar-plus syndromes, VEP, BAEP and SEP abnormalities were more frequent in inherited cases (ADCA I and II, along with autosomal recessive LOCA) than in sporadic ones. The most apparent differences were a higher incidence of abnormal BAEPs at brainstem level (p < 0.002), and of both peripheral and possible central SEP impairment in hereditary cerebellar-plus syndrome than in sporadic cerebellar-plus syndrome (p < 0.03). EP investigation is useful to a certain extent in differentiating between some variants of LOCA.

Adult↗
PubMedDate not supplied

Electro-oculogram in multiple system and late onset cerebellar atrophies.

The present investigation uses electrooculogram to evaluate multiple system atrophy (MSA) and late onset cerebellar atrophies (LOCAs), both idiopathic (ILOCA) and late onset autosomal dominant cerebellar ataxia (ADCA). Forty cases were clinically examined using scales for cerebellar, pyramidal, parkinsonian, mental status and neuroimaging quantitative evaluations. The patients were classified into three groups: olivopontocerebellar atrophy (OPCA), striatonigral degeneration (SND), Shy-Drager syndrome (SDS), and LOCA. We have used direct current electro-oculography in order to establish their validity in making the diagnosis. Cerebellar signs were significantly correlated with impaired VOR-fix gain and OKN, abnormalities of saccades, and reduced smooth pursuit gain (p < 0.05). Pons atrophy was significantly correlated with impaired VOR-fix gain (p < 0.01), abnormalities of saccades (p < 0.01), and reduced smooth pursuit gain (p < 0.05). Cerebellar hemisphere atrophy was significantly correlated only with impaired VOR-fix gain (p < 0.05), and medulla oblongata atrophy only with abnormalities of saccades (p < 0.05). Gaze-evoked nystagmus was found in 42.8% of patients with OPCA, and only in 14.2% with SND, but was not found in LOCA patients (t test, p < 0.05). In patients with OPCA, the combination of gaze-evoked nystagmus, abnormalities of sinusoidal VOR and reduced OKN gain measurements was very frequent, while infrequent in both LOCA (Fisher's exact test, p < 0.05) and SND subjects (p < 0.01). SDS also showed abnormalities of the oculomotor system.

Adult↗
PubMedDate not supplied

Cerebrotendinous xanthomatosis diagnosed after traumatic subdural haematoma.

We report the case of a 34-year old man, who, after presenting with subacute traumatic subdural haematoma, was diagnosed as CTX. He presented a ten year history of progressive deterioration of cognitive functions, unsteadiness of gait and surgery for bilateral cataracts at age 21. Cholestanol level in serum was 120.7 mmol/liter, and cholestanol/cholesterol ratio 2.52%. Bile alcohols in urine were 23, 25-pentol: 2.2665 mg/mmol creatinine, 24, 25-pentol: 1.3226 mg/mmol creatinine, and 27-nor-24, 25-pentol: 0.7363 mg/mmol creatinine. Electrophysiological study was consistent with a mixed demyelinating and axonal neuropathy. The assessment of autonomic nervous system (ANS) showed a postganglionic cholinergic failure accompanying somatic peripheral neuropathy. Brain-stem auditory evoked potentials (BAEPs) demonstrated markedly low amplitude and poorly defined waves, and almost symmetrical peak V and I to V interpeak latency (IPL) slight delays. Two nodular, bilateral, symmetrical lesions, strongly suggestive of calcifications, in the cerebellar white matter on CT and MRI were noted. On T2-weighted images diffuse high signal lesions were found in the cerebellar white matter, and multiple, hyperintense cerebral foci of demyelination or gliosis. MRI study of the Achilles tendon showed neither enlargement of the tendon, nor areas of lipid deposits. After ten months of treatment with chenodeoxycholic acid (CDCA) (750 mg/d) the clinical course was unaffected and the neurophysiological measures, CT and MRI remained unchanged.

Adult↗