1. The Central Nervous System

2. Pathology of the Central Nervous System

3. Cerebrovascular Diseases

8. Hypoxia, Ischemia, and Infarction

14. Cerebral infarction. A, At low magnification, it is possible to see the demarcated areas of an acute infarction. In the underlying white matter, the areas of infarction are well shown by the myelin stain. B, Acute ischemic injury causes diffuse eosinophilia of neurons, which are beginning to shrink. C, infiltration of a cerebral infarct by neutrophils begins at the edges of the lesion where vascular supply has remained intact. D, After about 10 days, an area of infarction is characterized by the presence of macrophages and surrounding reactive gliosis. E, Remote small intracortical infarcts are seen as areas of tissue loss with a small amount of residual gliosis.

22. A, Sections of the brain showing a large, discolored, focally hemorrhagic region in the left middle cerebral artery distribution (hemorrhagic, or red, infarction)

23. C, A bland infarct with punctate hemorrhages, consistent with ischemia-reperfusion injury, is present in the temporal lobe.

27. Intracranial Hemorrhage

34. Common sites of saccular (berry) aneurysms in the circle of Willis

41. Hypertensive Cerebrovascular Disease

44. Lacunar infarcts in the caudate and putamen.

48. Demyelinating Diseases

50. Multiple Sclerosis

55. Multiple sclerosis. Section of fresh brain showing brown plaque around occipital horn of the lateral ventricle.

59. Multiple sclerosis. A, Unstained regions of demyelination (MS plaques) around the fourth ventricle (Luxol fast blue PAS stain for myelin). B, Myelin-stained section shows the sharp edge of a demyelinated plaque and perivascular lymphocytic cuffs. C, The same lesion stained for axons shows relative preservation.

66. Multiple Sclerosis Variants

69. Acute Disseminated Encephalomyelitis and Acute Necrotizing Hemorrhagic Encephalomyelitis

72. Other Diseases With Demyelination

76. Degenerative Diseases

80. Degenerative Diseases Affecting the Cerebral Cortex

82. Alzheimer Disease

85. Alzheimer disease with cortical atrophy most evident on the right, where meninges have been removed.

87. Alzheimer disease. A, Neuritic plaque with a rim of dystrophic neurites surrounding an amyloid core.

90. Alzheimer Disease. B, Congo red stain of the cerebral cortex showing amyloid deposition in the blood vessels and the amyloid core of the neuritic plaque (arrow)

91. Alzheimer Disease. C, Neurofibrillary tangles (arrowheads) are present within the neurons.

98. Frontotemporal Dementias

115. Degenerative Diseases of Basal Ganglia and Brainstem

117. Parkinsonism

121. Parkinson Disease

126. Multiple System Atrophy

130. Huntington Disease

133. Huntington disease (HD). Normal hemisphere on the left compared with the hemisphere with HD on the right showing atrophy of the striatum and ventricular dilation.

136. Spinocerebellar Degenerations

138. Spinocerebellar Ataxias

145. Degenerative Diseases Affecting Motor Neurons

148. Amyotrophic Lateral Sclerosis (Motor Neuron Disease)

151. Amyotrophic lateral sclerosis. Spinal cord showing loss of myelinated fibers (lack of stain) in corticospinal tracts. The anterior roots are smaller than the posterior roots.

154. Bulbospinal Atrophy (Kennedy Syndrome)

156. Spinal Muscular Atrophy

158. Genetic Metabolic Diseases

162. Leukodystrophies

163. Krabbe Disease

166. Metachromatic Leukodystrophy

170. Metachromatic leukodystrphy. Demyelination is extensive. The subcortical fibers in the cerebral hemisphere are spared (Luxol fast blue PAS stain for myelin)

171. Adrenoleukodystrophy

173. Pelizaeus-Merzbacher Disease

175. Canavan Disease

177. Mitochondrial Encephalomyopathies

179. Leigh Syndrome (Subacute Necrotizing Encephalopathy)

182. Other Mitochondrial Encephalomyopathies

185. Toxic and Acquired Metabolic Diseases

186. Vitamin Deficiencies

187. Thiamine (Vitamin B 1 ) Deficiency

190. Vitamin B 12 Deficiency

192. Neurologic Sequelae of Metabolic Disturbances

193. Hypoglycemia

196. Hyperglycemia

198. Hepatic Encephalopathy

200. Toxic Disorders

201. Carbon Monoxide

203. Methanol

205. Ethanol

207. Alcoholic cerebellar degeneration. The anterior portion of the vermis (upper portion of figure) is atrophic with widened spaces between the folia.

208. Radiation

210. Combined Methotrexate and Radiation-Induced Injury

213. Tumors

218. Gliomas

222. Well-differentiated astrocytoma. A, the right frontal tumor has expanded gyri, which led to flattening (arrows).

224. B, Glioblastoma multiforme appearing as a necrotic, hemorrhagic, infiltrating mass.

228. Glioblastoma. Foci of necrosis with pseudopalisading of malignant nuclei. Also, glomeruloid body.

235. Pilocytic astrocytoma in the cerebellum with a nodule of tumor in a cyst.

242. Ependymoma. A, Tumor growing into the fourth ventricle, distorting, compressing, and infiltrating surrounding structures.

244. Ependymoma. B, Microscopic apearance of ependymoma.

250. Neuronal Tumors

254. Poorly Differentiated Neoplasms

257. Medulloblastoma. B, Sagittal section of brain showing medulloblastoma destroying the superior midline cerebellum.

258. Medulloblastoma. C, Microscopic appearance of medulloblastoma.

265. Other Parenchymal Tumors

270. Meningiomas

272. A, parasagittal multilobular meningioma attached to the dura with compression of underlying brain. B, Meningioma with a whorled pattern of cell growth and psammoma bodies.

277. Metastatic Tumors

279. Paraneoplastic Syndromes

282. Peripheral Nerve Sheath Tumors

286. Schwannoma. A, Bilateral eighth nerve schwannomas.

287. Schwannoma. B, Tumor showing cellular areas, including Verocay bodies (far right), as well as looser, myxoid regions.

291. Credits Books: PBD, 7th Ed. Photos: PBD Interactive Case Study Companion Elsevier Internet: http://www.med.uottawa.ca/patho/neuro/introneuropathology.h tm http://www.radnet.ucla.edu/sections/DINR/Part%2013/Part13A2.h tm