Radicular lesions in tuberculous meningitis. A clinicopathological study

In the present work, the involvement of cranial and spinal nerve roots in tuberculous meningitis was studied. Cranial nerves of 11 cases and the spinal roots of three patients were examined by means of serial sections of the base of the brain, brainstem and spinal cord. Although entrapment of the nerves by the tenacious inflammatory exudate was prominent, vasculitis lesions of the cranial nerves and spinal roots were also frequently observed. The latter could be an additional cause of nerve palsies in tuberculous meningitis.     

Congenital hypomyelination neuropathy: Glial bundles in cranial and spinal nerve roots

Autopsy examination of a 31/4-year-old child with a severe congenital hypomyelination neuropathy showed the anterior spinal nerve roots and motor cranial nerves to be almost devoid of myelin in their subarachnoid course. The posterior spinal nerve roots and peripheral nerves were less severely affected. Onion bulb formation was minimal and was present only in the sural nerve. There was extensive glial overgrowth in cranial nerves and spinal nerve roots adjacent to the brainstem and spinal cord. The extent and severity of glial overgrowth were similar to that described in Werdnig-Hoffmann disease and morphologically appeared as glial bundles. These glial bundles are most likely secondary to chronic myelin and axonal damage.     

Demyelinating radiculopathy in the kearns-sayre syndrome: A clinicopathological study

In the few previously autopsied patients with the Kearns-Sayre form of progressive ophthalmoplegia, the most prominent abnormalities have been in muscle, with less conspicuous changes in the central nervous system, primarily in the brainstem. Similar findings were present in the case reported here, but in addition there was severe demyelination in the initial few millimeters of the cranial and spinal motor roots distal to the glial-Schwann cell junction. Milder demyelination was observed in the dorsal spinal and afferent cranial nerve roots, including the eighth nerve, but deafness was due to virtually total destruction of the organ of Corti. Our observations suggest that a radiculopathy may be a feature in some cases of Kearns-Sayre syndrome.     

Distribution of dorsal root fibers in the medulla oblongata of the cat

Afferent fibers to the medulla oblongata of the cat were studied in 25 animals following section of one or more dorsal roots. Using the Nauta-Laidlaw stain a map was constructed of the distribution of the fibers to the dorsal column nuclei and a survey made of the afferents to other bulbar nuclei: nucleus cuneatus lateralis, lateral reticular nucleus, descending root of the fifth cranial nerve and the nucleus tractus solitarii. In the intermediate segment of the nucleus gracilis and the caudal two thirds of the nucleus cuneatus, there is a somatotopical arrangement with a dorso-ventral and medio-lateral shifting of the fibers from the dorsal roots as one goes from caudal segments to more cranial ones. A bilateral projection is demonstrated in the nucleus gracilis after section of nearly all the coccygeal-sacro-lumbar-thoracic roots; the contralateral degeneration is confined to the rostral pole of the nucleus gracilis. No bilateral degeneration is found in the nucleus cuneatus after section of the roots projecting to it. Degenerated axons in the nucleus cuneatus lateralis and in the lateral reticular nucleus are always present beginning from T6–T7 while in the descending root of the fifth cranial nerve they are recognizable in only one case with a section of the third sacral root.     

Vascular compression, hemifacial spasm, and multiple cranial neuropathy

Hemifacial spasm is usually an isolated symptom resulting from facial nerve root compression. Three patients had, in addition, tinnitus, hearing loss, facial sensory loss, diminished gag reflex, dysphagia, and dysarthria. Acoustic reflexes were abnormal, and facial nerve conduction studies showed evidence of ephaptic transmission and ectopic excitation. Brain CT and metrizamide cisternography were normal. Surgical exploration showed compression of cranial nerve roots by posterior inferior cerebellar artery branches. After decompression, symptoms abated, and electrical signs of hemifacial spasm disappeared. Vascular compression of nerve roots in the cerebellopontine recess may cause multiple cranial neuropathy.     

Unusual case of multiple cellular and malignant schwannomas of the cranial and spinal nerves

Schwannomas from cranial nerves and spinal roots are most often benign, malignant schwannomas being uncommon in this location. This report describes a unique case of multiple cellular and malignant schwannomas of the cranial and spinal nerves in a patient with features of neurofibromatosis 2. The tumors were arising from left optic, bilateral oculomotor, trochlear, abducent and vestibular nerves, the left facial and the spinal lumbar nerve roots. The tumor arising from the right trochlear nerve was seen excavating into the hippocampus and the left vestibular nerve into the medulla. In addition, the patient had nodular schwannomas adherent to the inferior surface of the optic chiasm and the cerebellum away from the cranial nerves. Hyperplastic schwannosis was noted in perivascular spaces of thalamus, cerebellum and hippocampus on both sides away from the main lesions. The immunohistochemical and ultrastructural profiles of the tumors suggest that neurofibromas and schwannomas are probably not distinct tumors but lie within a spectrum that differs histologically depending on the predominant cell type.     

An autopsy case of meningeal carcinomatosis with parenchymal invasion through the cranial and spinal nerve roots

Meningeal carcinomatosis is a well‐known complication of malignant neoplasms. We report a case of meningeal carcinomatosis of 2 months' duration in a 22‐year‐old man, in whom the initial symptom was gradually worsening headache. Postmortem examination revealed infiltrating adenocarcinoma of the stomach. Carcinoma cells showed diffuse spread to the subarachnoid space of the brain and spinal cord. In many places, subarachnoid tumor cells had infiltrated to the cranial and spinal nerves. Moreover, carcinoma cells in the nerve roots extended to the parenchyma of the brain and spinal cord beyond the CNS‐peripheral nervous system junction. These findings suggest that cranial and spinal nerve roots can be a possible route of parenchymal invasion in meningeal carcinomatosis.     

Preservation of segmental hindbrain organization in adult frogs

To test for possible retention of early segmental patterning throughout development, the cranial nerve efferent nuclei in adult ranid frogs were quantitatively mapped and compared with the segmental organization of these nuclei in larvae. Cranial nerve roots IV-X were labeled in larvae with fluorescent dextran amines. Each cranial nerve efferent nucleus resided in a characteristic segmental position within the clearly visible larval hindbrain rhombomeres (r). Trochlear motoneurons were located in r0, trigeminal motoneurons in r2-r3, facial branchiomotor and vestibuloacoustic efferent neurons in r4, abducens and facial parasympathetic neurons in r5, glossopharyngeal motoneurons in r6, and vagal efferent neurons in r7-r8 and rostral spinal cord. In adult frogs, biocytin labeling of cranial nerve roots IV-XII and spinal ventral root 2 in various combinations on both sides of the brain revealed precisely the same rostrocaudal sequence of efferent nuclei relative to each other as observed in larvae. This indicates that no longitudinal migratory rearrangement of hindbrain efferent neurons occurs. Although rhombomeres are not visible in adults, a segmental map of adult cranial nerve efferent nuclei can be inferred from the strict retention of the larval hindbrain pattern. Precise measurements of the borders of adjacent efferent nuclei within a coordinate system based on external landmarks were used to create a quantitative adult segmental map that mirrors the organization of the larval rhombomeric framework. Plotting morphologically and physiologically identified hindbrain neurons onto this map allows the physiological properties of adult hindbrain neurons to be linked with the underlying genetically specified segmental framework.     

α‐Synuclein pathology in the cranial and spinal nerves in Lewy body disease

Accumulation of phosphorylated α‐synuclein in neurons and glial cells is a histological hallmark of Lewy body disease (LBD) and multiple system atrophy (MSA). Recently, filamentous aggregations of phosphorylated α‐synuclein have been reported in the cytoplasm of Schwann cells, but not in axons, in the peripheral nervous system in MSA, mainly in the cranial and spinal nerve roots. Here we conducted an immunohistochemical investigation of the cranial and spinal nerves and dorsal root ganglia of patients with LBD. Lewy axons were found in the oculomotor, trigeminal and glossopharyngeal‐vagus nerves, but not in the hypoglossal nerve. The glossopharyngeal‐vagus nerves were most frequently affected, with involvement in all of 20 subjects. In the spinal nerve roots, Lewy axons were found in all of the cases examined. Lewy axons in the anterior nerves were more frequent and numerous in the thoracic and sacral segments than in the cervical and lumbar segments. On the other hand, axonal lesions in the posterior spinal nerve roots appeared to increase along a cervical‐to‐sacral gradient. Although Schwann cell cytoplasmic inclusions were found in the spinal nerves, they were only minimal. In the dorsal root ganglia, axonal lesions were seldom evident. These findings indicate that α‐synuclein pathology in the peripheral nerves is axonal‐predominant in LBD, whereas it is restricted to glial cells in MSA.     

On the occurrence of oligodendroglia-like areas in neurinomas experimentally induced in the rat by nitrosourea derivatives

In 21 out of 112 neurinomas, mostly of the Vth cranial nerve, experimentally induced in the rat by nitrosourea derivatives, i.e. MNU and ENU, tumour areas with an oligodendroglial appearance were noted and are illustrated histologically. Their origin as a result of regressive events in the tumour or from differentiation of Schwann tumour cells is regarded as unlikely.On the grounds of their topographical situation in the tumour and the existence of associated oligodendrogliomas of the central and intrapontine part of the root, the hypothesis is put forward that they represent the effect of cancerogenic stimulation of the central part of the roots. The particular sensitivity of the Vth cranial nerve in the rat to the effects of nitrosourea derivatives is also emphasized.     

Anomalies of the lumbosacral nerve roots

The congenital anomalies of the lumbosacral nerve roots have frequently been found in the past as operative findings during surgery for protruded disc and are today diagnosed preoperatively with increasing frequency. They include the more cranial or more caudal origin of a nerve root, the conjoined structure of two roots and the anastomoses between two or more roots. This study reviews the large amount of literature on these anomalies and discusses their incidence, classification and embryological origin, the anatomical structure of the anomalous roots, their clinical presentation and radiological diagnosis. Anomalous nerve roots are often asymptomatic; radicular symptoms may appear in the presence of a protruded disc or lumbar stenosis, as a result of the compression or traction of the anomalous root. Myelography with water-soluble contrast media allows a good visualization of the root sheaths and thus a good diagnostic definition of these anomalies. In symptomatic cases, the surgical treatment consists of the removal of the disc hernia, associated with hemilaminectomy and foraminotomy, to obtain a good mobilization of the anomalous root; it usually results in the remission of the radicular symptoms.     

Multiple schwannomas of the sciatic nerve.

Schwannomas are rare benign tumours of nerve sheath cells of neural crest origin. Often these tumours are solitary and encapsulated. Multiple schwannomas can arise from the peripheral nervous system including cranial nerves, spinal roots, the brachial and lumbar-sacral plexus or major peripheral nerves. We report an extremely rare case of schwannomatosis of the sciatic nerve in a young female and include a comprehensive literature review. Treatment options are discussed.     

Unmyelinated axons in the trigeminal motor root of human and cat

The fiber composition of the human and cat trigeminal “motor roots” were studied utilizing the electron microscope. Twelve to twenty percent of fibers in the human trigeminal motor root are unmyelinated whereas 9–15% are unmyelinated in the cat. The only previous examination of the fiber composition of the peripheral trigeminal motor nerve utilized the light microscope and indicated that less than 5% of fibers were unmyelinated in cat. No study of the fiber composition of the motor nerve root is available. The present results are similar to those recently obtained by others for spinal ventral roots. The function of unmyelinated fibers in the trigeminal “motor root” is unknown, however indirect evidence, both laboratory and clinical, suggests a potential sensory function for them. The findings question seriously the concept that the functional separation of the nervous system into motor and sensory systems has anatomical correlates in the spinal and cranial nerve roots. The results relate directly to our conceptualization of the nervous system and also to the design of methods for the treatment of intractable pain.     

Malignant meningioma metastasizing through the cerebrospinal pathways.

A 53-year old man presented with a malignant meningioma which was incompletely removed. The tumour subsequently metastasized through the cerebrospinal pathways causing clinical signs through invasion of the cranial nerve roots. Microscopically, the metastatic deposits displayed a papillary pattern and increased anaplastic cytological features.     

Ectopic discharges and adrenergic sensitivity of sensory neurons after spinal nerve injury

At various times after spinal nerve injury, dorsal root ganglia (DRGs) from injured segments were removed with attached dorsal roots and spinal nerves. In an in vitro recording chamber, spontaneously active units were recorded from teased dorsal root fascicles. Sustained spontaneous activity could first be recorded at 13 h after the ligation, but adrenergic sensitivity did not develop until 24 h after the injury. Almost all recorded activity originated from the DRG. Thus, the DRG is the most common site for ectopic discharge generation after spinal nerve injury and separate mechanisms seem to be involved in the development of ectopic discharges and adrenergic sensitivity.     

A case of Möbius syndrome presenting with symptoms of severe infantile form of congenital muscular disorder

M?bius syndrome is a rare disorder characterized by congenital bilateral facial nerve palsy. Abducent palsy or other cranial nerve palsy, facial malformations, limb malformations, and skeletal malformations are common features associated with this syndrome. We report a 9-month-old infant in whom congenital muscular disorder was previously suspected because of facial muscle involvement (mask-like face), respiratory and swallowing disturbances, and hypotonia since birth. After an improvement in the respiratory infection, she showed slightly exaggerated deep tendon reflexes and an improvement in muscle tone. The occurrence of combined facial nerve palsy, glossopharyngeal nerve palsy, vagus nerve palsy, and hypoglossal nerve palsy strongly suggested that she had M?bius syndrome. Finally, the absence of the roots of bilateral facial nerves on an MRI confirmed that the disorder was M?bius syndrome. We propose that a thin slice MRI should be obtained to observe the cranial nerves around the brain stem if patients show symptoms of congenital myopathy or congenital myotonic dystrophy as well as facial nerve and other cranial nerve paralyses.     

Severe cranial nerve involvement in longstanding demyelinating polyneuropathy: a clinicopathologic correlation

Onion bulb formations involving cranial nerves are an unusual pathologic feature. We report the postmortem neuropathologic findings in a 69-year-old man with a longstanding neuropathy characterized by progressive muscle weakness, sensory ataxia and multiple cranial nerve abnormalities. Electrodiagnostic testing disclosed features of an acquired demyelinating polyneuropathy. Treatment with corticosteroids and plasmapheresis resulted in no change in his neurologic status, and the patient died after repeated episodes of pneumonia and sepsis. Autopsy showed widespread onion bulb formation in cranial nerves III, IV, V, VI, X, XI and XII, anterior and posterior spinal nerve roots, dorsal root ganglia and multiple peripheral nerves, some of which also had foci of epineurial perivascular inflammation. Muscle sections revealed severe neurogenic atrophy. This case demonstrates that, in longstanding acquired demyelinating neuropathy, the cranial nerves also undergo repetitive cycles of demyelination and remyelination resulting in severe weakness of the bulbar musculature and histologic features of hypertrophic neuropathy. Received: 29 May 1995 / Revised, accepted: 25 September 1995     

Sarcoid peripheral neuropathy.

We studied 10 patients with sarcoidosis and peripheral neuropathy. Six had a subacute or chronic axonal sensorimotor neuropathy without cranial neuropathy, beginning months to years after established systemic sarcoidosis. One patient had severe enough diaphragmatic weakness to require mechanical ventilation. Four patients had atypical neuropathies: acute Guillain-Barré syndrome, mononeuritis multiplex, unilateral lumbosacral plexopathy, and a purely sensory neuropathy, all before systemic sarcoidosis became evident, and all except one had cranial nerve abnormalities. Autopsy in one patient with sensorimotor neuropathy showed only scattered foci of lymphocytes in spinal roots and ganglia with nerve fiber loss.     

Postnatal development of adrenergic innervation in the tibial and vagus nerves of Fischer-344 rats

Adrenergic innervation of rat tibial and vagus nerves was studied in male Fischer-344 rats between 1 and 84 days of age, using sucrose-phosphate-glyoxylic acid (SPG) histochemistry and the formaldehyde-induced fluorescence (FIF) method. Adrenergic nerve fibers were found in epi-perineurial blood vessels of the vagus nerve at one day of age, whereas blood vessels in the tibial nerve received the first adrenergic nerve fibers at 3 days. A few adrenergic nerve fibers were seen in the endoneurium of both tibial and vagus nerves at 7 days. The densities of adrenergic innervation increased gradually during the first 4 postnatal weeks, and at 21 days the distributions of adrenergic innervation in both nerves resembled those in adult animals. The results suggest that development of adult adrenergic innervation in rat peripheral nerves occurs during the first postnatal month and that sympathetic innervation becomes available to regulate nerve blood flow within this period.     

微血管减压术治疗舌咽神经痛的手术体会及解剖学发现

目的 总结舌咽神经痛微血管减压术经验,探讨舌咽神经疼痛发生的解剖学基础.方法 所有病例均采用全身麻醉,乙状窦后入路微血管减压术.结果 首次12例患者术后疼痛症状完全消失,2例症状无明显缓解.12例患者术中发现血管压迫,责任血管为一根或多根;该12例患者中,10例责任血管接触神经根,但神经根无明显压痕;2例神经根出脑干部位有明显压痕.11例术中发现后组脑神经局部蛛网膜增厚并与神经粘连,其中8例舌咽神经走行正常,3例神经根移位、扭曲,蛛网膜粘连使其固定.有血管压迫的12例患者中,责任血管压迫神经根出脑干区5例,在神经中部4例,靠近颈静脉孔3例.结论 微血管减压术能有效治疗舌咽神经痛,血管压迫存在于舌咽神经颅内段全段,蛛网膜粘连使神经根固定,促进血管压迫形成,血管压迫舌咽神经多无明显压痕.