Thomas P. Naidich

Newborn screening for Krabbe disease: the New York State model.

Krabbe disease is a rare inherited neurologic disorder affecting the central and peripheral nervous systems. The disease has four phenotypes: early infantile, later onset, adolescent, and adult. The only known treatment is hematopoietic stem cell transplantation, which is, in the early infantile form of the disease, most beneficial if performed before onset of clinical symptoms. In August 2006, New York State began screening all newborns for Krabbe disease. A rapid and accurate technique for assessing galactocerebrosidase activity and performing DNA mutation analysis had been developed. Interpreting these results was limited, however, because neither enzyme activity nor genetic mutation reliably predicts phenotype. A series of initiatives were therefore developed by a multidisciplinary group of neurologists, geneticists, metabolic pediatricians, neurodevelopmental pediatricians, and transplant physicians (the Krabbe Consortium of New York State) to enhance the effectiveness of the newborn screening program. A standardized clinical evaluation protocol was designed based on the available literature, criteria for transplantation for the early infantile phenotype were formulated, a clinical database and registry was developed, and a study of developmental and functional outcomes was instituted. This multidisciplinary standardized approach to evaluating infants who have positive results on newborn screening may serve as a model for other states as they begin the process of screening for Krabbe disease and other lysosomal storage disorders.

Evaluation of Sellar and Parasellar Masses by Computed Tomography

Computed tomography is the method of choice for initial evaluation of patients with potential suprasellar masses. In our experience, CT has proved completely reliable for detecting or ruling out the presence of a suprasellar mass, the direction and degree of parasellar extension, and the presence of any calcific or cystic component of the lesion. When multiple cut CT has been negative, further diagnostic studies have proved unrewarding. When CT has been positive, additional studies have been required in some cases to rule out aneurysm prior to craniotomy.

Evaluation of Pediatric Hydrocephalus by Computed Tomography

Computed tomography (CT) is a safe and reliable technique for the study of children with increased head circumference. Hydrocephalic children requiring drainage of cerebrospinal fluid may be shunted on the basis of the CT scan alone and their postsurgical course followed by serial CT scans thereafter. Any additional pneumographic studies required may be performed via the existing shunt tube, eliminating transcerebral catheterization and its attendant complications.

Computed tomography in the diagnosis of extra-axial posterior fossa masses

Extra-axial posterior fossa masses can be diagnosed reliably by computed tomography (CT) in most cases. Acoustic and trigeminal neurinomas, meningiomas, cholesteatomas, and other extra-axial masses can usually be distinguished from intra-axial masses by asymmetric widening of the basal subarachnoid spaces, bone destruction, continuity of the tumor mass with the tentorium or bone, and more sharply defined margins. Multiple-cut study of the posterior fossa improved visualization of the fourth ventricle and basal cisterns. Interpretation of cisternal changes in association with changes in the fourth ventricle and abnormal attenuation coefficients permits accurate diagnosis of posterior fossa masses.

Dense Intracranial Epidermoid Tumors

Three extra-axial posterior fossa epidermoid tumors manifested nearly identical CT appearance of large size, sharp margination, apparently homogeneously increased attenuation in the range of 80-120 Hounsfield units, and absence of contrast-agent enhancement. This constellation of findings is distinctly different from that reported previously, and appears to be characteristic for some epidermoid tumors.

Spontaneous intracranial hypotension with pachymeningeal enhancement on MRI

Spontaneous intracranial hypotension (SIH) is a rarely reported syndrome of spontaneously occurring postural cephalalgia associated with low CSF pressure. We report a case of SIH in which MRI of the brain revealed diffuse symmetric pachymeningeal enhancement that resolved without specific therapy.

Central Nervous System Lymphoma Characterization by Diffusion‐Weighted Imaging and MR Spectroscopy

The characterization and differentiation of central nervous system (CNS) lymphoma has important diagnostic, therapeutic, and prognostic significance. The purpose of this study is to characterize the diffusion‐weighted imaging (DWI) and MR spectroscopic (MRS) findings in CNS lymphoma.

Ring Blush Associated with Intracerebral Hematoma

Seven cases of ring blush following spontaneous and post-traumatic, subacute and chronic intracerebral hematoma are presented. As such a hematoma ages, a ring blush may be seen following contrast-agent enhancement. Serial CT demonstrates disappearance of the ring blush from two to six months after the first scan. The CT appearance of the ring blush is not specific for hematoma, but its peripheral location and lack of mass effect may be considered suggestive of hematoma with appropriate clinical findings. The characteristic serial changes permit correct diagnosis without surgical intervention in most cases.

Superior oblique myokymia: magnetic resonance imaging support for the neurovascular compression hypothesis.

Superior oblique myokymia is a rare movement disorder thought to be caused by vascular compression of the trochlear nerve. Direct display of such neurovascular compression by magnetic resonance imaging has been lacking. The goal of this study was to assess the presence of neurovascular contacts in patients with superior oblique myokymia, using a specific magnetic resonance imaging protocol. A total of 6 patients suffering from right superior oblique myokymia underwent detailed neuro‐ophthalmological examination, which showed tonic or phasic eye movement. All patients underwent magnetic resonance imaging, using a magnetic resonance imaging Fourier transform constructive interference in steady‐state sequence in combination with magnetic resonance imaging time of flight magnetic resonance arteriography both before and after the administration of Gd‐DTPA. With this protocol, the trochlear nerve could be visualized on 11 of 12 sides (92%). Arterial contact was detected at the root exit zone of the symptomatic right trochlear nerve in all 6 patients (100%). No arterial contact was identified at the root exit zone of the asymptomatic left trochlear nerve in any of the 5 left nerves visualized. In conclusion, superior oblique myokymia can result from neurovascular contact at the root exit zone of trochlear nerve, and therefore should be considered among the neurovascular compression syndromes.

The Chiari II malformation: Part IV. The hindbrain deformity

SummaryComputed tomography successfully delineates the multiple components of the Chiari II malformation at the craniocervical junction, the hindbrain, and the cervical spinal cord. These include wide foramen magnum and upper cervical spinal canal; incomplete fusions of the posterior arches of C1 and lower cervical vertebrae; cascading protrusions of vermis, fourth ventricle, medulla, and cervical cord into the spinal canal; cervicomedullary “kinking”; anterior displacement and sequential sagittal compression of each protrusion by the protrusions posterior to it; compression of all protrusions by the posterior lip of foramen magnum and the posterior arch of C1; and associated cervical hydromyelia, cervical diastematomyelia, and cervical arachnoid cysts.