Neurodegenerative diseases of childhood: MR and CT evaluation

To evaluate the diagnostic utility of MR and CT in neurodegenerative diseases of childhood, we examined 63 children (MR in 44, CT in 53) carrying diagnoses of Leigh disease (14 patients), various metabolic diseases (13 patients), leukodystrophies (13 patients), other specific degenerative diseases (10 patients), and unclassified neurodegenerative disorders (13 children). Magnetic resonance yielded positive findings in 86% and CT in 81%. Lesion extent and conspicuity were consistently greater with MR. The high frequency of abnormalities detected on MR, and to a lesser extent on CT, helps distinguish children with neurodegenerative diseases from those with nonprogressive idiopathic movement disorders. The most common abnormalities included signal alterations (MR) or decreased attenuation (CT) of the basal ganglia and cerebral white matter, as well as local or generalized brain atrophy. Although considerable overlap was present, the findings showed four general patterns that may assist in tentative classification of patients with nonspecific clinical and laboratory findings.     

Suprasellar lesions: evaluation with MR imaging

The authors retrospectively evaluated the characteristics on magnetic resonance (MR) images of 59 suprasellar lesions and compared them with computed tomography (CT) scans in 55 of the cases in which CT was performed. A diverse number of lesions were included: 17 pituitary adenomas; eight optic or hypothalamic gliomas; six craniopharyngiomas; six vascular anomalies; four lesions with extension into the suprasellar space; three metastases; two each of meningioma, hamartoma, germinoma, sarcoid granuloma, and teratoma; and one each of lymphoma, optic tract hematoma, cerebrospinal fluid-borne metastasis, pituitary hyperplasia, and sphenoid sinus mucocele. MR enabled characterization of lesions containing hemorrhage, fat, flowing blood, mucus, and cyst and allowed more specific diagnoses than CT in 6% of cases. MR was equivalent to CT in allowing lesions to be detected and in 20% of cases more accurately defined altered perisellar anatomy. Vascular abnormalities can be better evaluated with MR, and use of angiography can be avoided in some cases.     

Efficacy of toxin-A Botulinum for treating intractable bladder hyperactivity in children affected by neuropathic bladder secondary to myelomeningocele: an alternative to enterocystoplasty

AIM: To verify the efficacy of botulinus toxin A (TB-A) in treating children with neuropathic bladder secondary to myelomeningocele (MMC) with detrusor hyperactivity/low compliance, resistance to pharmacological therapy, and candidates for enterocystoplasty. METHODS: From January 2002 to June 2003, a group of 7 patients was selected (4 females, 3 males, mean age, 9.8 years, age range, 5-17 years) with detrusor hyperactivity, clean intermittent catheterization and resistance to pharmacological therapy. Two patients presented with grade 2-3 monolateral vesicoureteral reflux (VUR). All patients were incontinent despite catheterization. Botulinus toxin A was administered under general or local anesthesia by the injection of 200 IU of toxin diluted in 10 cc of physiologic solution with a metal or a flexible needle (3.7 F/21 GA). The needle was fully inserted into the detrusor muscle in about 20 sites, and 0.5 cc of solution were injected in each site, except the trigonum vesicae. Follow-up included ultrasound examination of the urinary tract and urodynamic studies performed at 6, 12 and 24 weeks and biannually thereafter. Micturition cystography was performed 3 months after the intervention. Urodynamic parameters were leak point pressure (LPP), leak point volume (LPV) and specific volume at 20 cm H2O pressure. The results were analyzed using the Wilcoxon test. RESULTS: A significant increase in LPV (range, 30-108%, mean, 77.6%) and in specific volume at 20 cm H2O pressure (CS 20) was observed in all patients. No significant change in LPP was found. One patient previously treated with the Cohen reimplantation technique experienced transient VUR which resolved spontaneously within 1 month. No major side effects from the injection of TB-A occurred. All patients were hospitalized for 24 hours with catheterization. CONCLUSIONS: The preliminary results in this small sample of patients suggest that the use of TB-A is efficacious in significantly improving urodynamic parameters and urine storage volume at low pressures in patients with neuropathic bladder resistant to pharmacological therapy.     

Desmopressin is a safe drug for the treatment of enuresis

OBJECTIVE: To verify the safety of desmopressin treatment and its associated side-effects in a large number of patients. MATERIAL AND METHODS: The study was conducted in accordance with the guidelines of the Italian Club for Nocturnal Enuresis, whose criteria are: age >5 years; absence of malformations and infections of the urinary tract; absence of psychological disorders or neurological alterations; number of "wet nights" >5-7; control of liquid intake during the afternoon and evening; monitoring of serum electrolytes before beginning treatment; control of body weight before the beginning of treatment and during the first 4-5 days of therapy; and the informed consent of the parents. The therapeutic regimen provided for a maximum dose of desmopressin of 40 microg/day (four puffs/nostril or two tablets), starting from an initial dosage of 20 microg/day (two puffs/nostril or one tablet) 1 h before going to bed. The study involved two groups of patients with monosymptomatic enuresis: some of them had been administered desmopressin in the form of a spray and others in the form of tablets. RESULTS: A small percentage of patients presented mild, transient side-effects; in no case were severe side-effects verified. CONCLUSION: Desmopressin is a safe drug with a low incidence of side-effects.     

Abnormalities of thalamic volume and shape in schizophrenia

OBJECTIVE: Postmortem and neuroimaging studies of schizophrenia have reported deficits in the volume of the thalamus and its component nuclei. However, the pattern of shape change associated with such volume loss has not been investigated. In this study, alterations in thalamic volume, shape, and symmetry were compared in subjects with and without schizophrenia. METHOD: T(1)-weighted magnetic resonance scans were collected in 52 schizophrenia and 65 comparison subjects matched for age, gender, race, and parental socioeconomic status. High-dimensional (large-deformation) brain mapping was used to assess thalamic morphology. RESULTS: Significant differences in thalamic volume, deformities of thalamic shape at the anterior and posterior extremes of the structure, and a significant exaggeration of thalamic asymmetry (i.e., left smaller than right) were found in the schizophrenia subjects. After covarying for total cerebral volume, the difference in thalamic volume became insignificant. When information about thalamic shape was combined with previously collected information about hippocampal shape, the discrimination between schizophrenia patients and comparison subjects was improved. CONCLUSIONS: Thalamic volume was smaller than normal in schizophrenia patients, but only proportionate to reductions in reduced total cerebral volume. The presence of changes in thalamic shape and asymmetry suggest greater pathologic involvement of individual nuclei at its anterior and posterior extremes of the thalamic complex.     

Untreated depression and hippocampal volume loss

OBJECTIVE: The purpose of this study was to investigate the effect of antidepressant treatment on hippocampal volumes in patients with major depression. METHOD: For 38 female outpatients, the total time each had been in a depressive episode was divided into days during which the patient was receiving antidepressant medication and days during which no antidepressant treatment was received. Hippocampal gray matter volumes were determined by high resolution magnetic resonance imaging and unbiased stereological measurement. RESULTS: Longer durations during which depressive episodes went untreated with antidepressant medication were associated with reductions in hippocampal volume. There was no significant relationship between hippocampal volume loss and time depressed while taking antidepressant medication or with lifetime exposure to antidepressants. CONCLUSIONS: Antidepressants may have a neuroprotective effect during depression.     

Aging, dementia, and brain atrophy: a longitudinal computed tomographic study

Studies involving linear measurements of ventricular size and a volumetric measurement of the cerebrospinal fluid (CSF) space were performed on elderly subjects with mild dementia of the Alzheimer type and on age-matched controls. Forty-five subjects were studied twice at a 1 year interval; linear ventricular measurements showed not only a greater degree but a more rapid evolution of brain atrophy in individuals with mild dementia as compared with controls. An additional 12 normal subjects were studied twice over a 1 year period with volumetric estimates of the CSF space, which demonstrated development of significant brain atrophy within 1 year, while linear measurements on the same scans showed no significant change. The volumetric method is regarded as a more sensitive indicator of brain volume and is potentially useful in further studies in dementia.     

Evaluation of the Suprasellar Cistern by Computed Tomography

The normal suprasellar cistern is a five- or six-pointed, starshaped, fluid-filled structure as demonstrated by computerized axial tomography (CAT). At various levels the normal suprasellar cistern contains the major intracranial vessels and their anastomotic channels, the optic nerves, chiasm, and infundibular stalk. The existence of lesions, either intrinsic structures of or extrinsic structures contiguous to the suprasellar cistern can be detected by their effect on the normal anatomy of the suprasellar cistern or by filling defects produced when studied with metrizamide cisternography.     

Computerized tomography of the orbit.

The potential for using CT to diagnose orbital lesions is clearly demonstrated in this chapter. The patients discussed were all suffering from proptosis and had other complaints such as visual disturbances, pain, or ophthalmoplegia. CT is superior to ultrasonography in its ability to reproduce anatomical structures, including the retroocular space, bony walls of the orbit, and extraorbital regions, such as ethmoid sinuses and the cranial cavity. Such reproduction helps distinguish lesions arising within the orbit from those invading the orbit from outside. CT not only defines the extent of a lesion but also provides information about the physical properties of the tissue. The remarkable difference on CT between proptosis caused by thyrotoxic disease and that caused by intraorbital tumor or pseudotumor is a striking example of the way in which CT may contribute to more accurate diagnosis.