Annotated Bibliography

Nolan Altman, James A. Brunberg, Allen D. Elster, Ajax E. George, David B. Hackney, Robert B. Lufkin, JeffreyS. Ross, Joel D. Swartz, Jane L. Weissman, and Samuel M. Wolpert

Brain Tumors and Cysts Aylward EH, Brandt J, Codori AM, Mangus RS, Barta PE, Harris GJ. Reduced volume associated with Peterson DL, Sheridan PJ, Brown WE Jr. Animal models the gene for Huntington's disease in asymptomatic at­ for brain tumors: historical perspectives and future direc­ risk persons. 1994;44:823-828. tions. J Neurosurg 1994;80:865-876. Volumes of the basal ganglia structures were signifi­ An excellent review of animal models available for those cantly reduced in asymptomatic at-risk siblings of Hun­ involved in brain tumor research. Included are spontane­ tington patients with marker-positive genes, but not in ous tumors, carcinogen-induced tumors, virus-induced siblings with marker-negative genes.O SMW tumors, models based on cell or tissue transplantation, and transgenic models. This paper is not for the general SchneiderS, Feifel E, Ott D, Schumacher M, Luking CH, reader, but will be of great interest to academicians and Deuschl G. Prolonged MRI T2 times of the lentiform nu­ researchers.O ADE cleus in idiopathic spasmodic . Neurology 1994; 44:846-850. Magnetic resonance (MR) findings in 22 patients with spasmodic torticollis were compared with those of 28 age­ Degenerative and Metabolic Disease and matched control subjects. T2 values in the putamen and Aging pallidum on both sides were significantly higher in the patients than in the controls. The authors speculate that Bensimon G, Lacomblez L, Meininger V, and the ALS/ the findings could represent focal gliosis.OSMW Riluzole Study Group. A controlled trial of riluzole in amyotrophic lateral sclerosis. N Eng/ J Med 1994;330: Rouanet F, Tison F, Dousset V, Corand V, Orgogozo JM. 585-591. Clinical/scientific notes: early T2 hypointense signal ab­ One hypothesis about the origin of amyotrophic lateral normality preceding clinical manifestations of central sclerosis implicates abnormal accumulation of glutamate pontine myelinolysis. Neurology 1994;44:979-980. (the primary excitatory central neuro­ In this interesting case report, the authors describe a transmitter) at . Experimentally, riluzole inhibits patient with central pontine myelinolysis in whom an MR the presynaptic release and postsynaptic actions of gluta­ study revealed hypointense signal on T2-weighted se­ mate. This double-blind, placebo-controlled, prospective quences in the basis pontis 1 week before the onset of study was carefully performed and analyzed. Survival in clinical signs of the disease while the patient was still the riluzole group was statistically greater than survival in markedly hyponatremic. On a second MR image obtained the placebo group; the effect was greatest in patients with 1 week later, the typical appearances of central pontine bulbar-onset amyotrophic lateral sclerosis, with only a myelinolysis, hypointense areas on T1-weighted and hy­ "trend" in patients with limb-onset disease. Riluzole also perintense on T2-weighted images, were seen.OSMW slowed the deterioration of muscle strength. So far, ther­ apy for amyotrophic lateral sclerosis has been inadequate. Graham SH , Meyerhoff DJ, Nat R, et al. Magnetic reso­ These results might constitute a breakthrough.OJLW nance spectroscopy of N-acetylaspartate in hypoxic­ ischemic . Ann Neuro/1994;35:490-494. Lipton SA, Rosenberg PA. Mechanisms of disease: exci­ Water-suppressed proton MR spectroscopic imaging tatory amino acids as a final common pathway for neu­ measurements of N-acetylaspartate may be a sensitive rologic disorders. N Eng/ J Med 1994;330:613-620. way to measure selective neuronal loss of patients with This review article clarifies some mechanisms briefly hypoxic-ischemic encephalopathy as shown in this single alluded to in the preceding article. Glutamate, the principal case report.ONA excitatory CNS neurotransmitter, is involved in cognition, memory, movement, sensation. Overstimulation of gluta­ mate receptors may cause "excitotoxicity" and cell death in acute (, trauma, hypoglycemia, ) and chronic injury (amyotrophic lateral sclerosis). The article goes into exquisite technical detail, but it is impor­ tant and worth skimming.OJLW

From Miami Children's Hospital (N.A.); University Hospital, Ann Arbor, Mich (J.A.B.); Bowman Gray School of Medicine, Winston-Salem, NC (A.D.E.); NYU Medical Center, New York (A.E.G .); Hospital of the University of Pennsylvania, Philadelphia (D.B.H.); UCLA School of Medicine, Los Angeles (R.B.L.); The Cleveland Clinic Foundation (J.S.R.); The Germantown Hospital and Medical Center, Ph iladelphia (J.D.S.); University of Pittsburgh School of Medicine (J.L.W. ); and New England Medical Center Hospital, Boston (S.M.W.).

AJNR 15:1596-1600, Sep 1994 0195-61 08/ 94/1508-1596 © American Society of Neuroradiology 1596 AJNR: 15, September 1994 ANNOTATED BIBLIOGRAPHY 1597

Hematologic Disorders Kuppersmith RB, Disher MJ, Deveikis JP, Frey K, Shulkin BL, Clevens RA, Wolf GT. Management of an osteogenic Case records of the Massachusetts General Hospital. sarcoma of the maxilla. Ann Otol Rhino/ Laryngol 1994; Weekly clinicopathological exercises: N Eng/ J Med 1994; 103:408-412. 330:920-927. Radionuclide bone scan, coronal CT, coronal pre- and Bilateral epistaxis, retinal hemorrhages, and bilateral postcontrast T1-weighted MR, anteroposterior angiogram, central-retinal-vein occlusions were among the clinical and a positron emission tomography scan are used to manifestations of "hyperviscosity syndrome." Plain films illustrate this lesion. Approximately 10% of all osteosarco­ of skull and hip showed lytic foci. "A diagnostic procedure mas are found in the head and neck region, most often in was performed": monoclonal protein identified in blood the mandible or maxilla. All maxillary osteosarcomas are and urine clinched the diagnosis of (did you guess?) mul­ believed to arise in the alveolar ridge. This case occurred tiple myeloma.DJLW in a 35-year-old man with a 115-pack per year smoking history who had undergone local excision of a smaller tumor 2 years before.D JDS

Inflammatory Disease Drobyski WR, Knox KK, Majewski D , Carrigan DR. Brief Neck and Nasopharynx report: fatal due to variant B human herpes­ Kerner MM, Bates ES, Hernandez F, Mickel RA. Carcino­ virus-6 infection in a bone marrow-transplant recipient. ma-in-situ occurring in a Zenker's diverticulum. Am J N Eng/ J Med 1994;330:1356-1360. Otolary ngol 1994; 15 ( 3): 223-226. This is the first documentation of Zenker Pharyngoesophageal Diverticulum results from infection by human herpesvirus-6. Autopsy revealed dam­ an outpouching in the inferior constrictor muscle known as age to astrocytes and myelin in frontal white matter, and to Killian Dehiscence. The authors present the sixth reported neurons in hippocampus gray matter. Other herpesvirus case of carcinoma-in-situ occurring within a Zenker diver­ infections have a propensity for the limbic system. Unfor­ ticulum. They emphasize that cigarette smoking, hemop­ tunately, no imaging studies are included.D JLW tysis, previous upper-aerodigestive-tract malignancy, and a prolonged history of the diverticulum have been identi­ Gilden DH. Herpes zoster with postherpetic neuralgia­ fied as risk factors.D JDS persisting pain and frustration. N Eng/ J Med 1994;330: 932-933. Stack MC, Ridley MB. Spontaneous cervical emphysema Postherpetic neuralgia is pain in one to three der­ in a child. Otolaryngol Head Neck Surg 1994;110:318- matomes after resolution of cutaneous herpes zoster in the 323. This is a long, mistitled case report of a child who (pre­ same distribution. Ongoing ganglion (zoster sumably) performed repeated Valsalva maneuvers, caus­ sine herpete) may cause postherpetic neuralgia. Current ing alveolar rupture. The authors state that all "spontane­ doses of oral acyclovir are not effective, but higher oral ous" cervical emphysema has a cause " if closely studied." doses, or intravenous therapy, may attenuate or eliminate Their bias is apparent: this is really an article on various the pain. Good news for sufferers.DJLW causes of cervical emphysema. Captions for the two plain films (neck, chest) and lung-window CT images (neck, chest) describe arrows pointing to the emphysema, but the arrows are nowhere to be seen.D JLW Mandible and Maxilla Mori H, Nishimura Y, Satomi F, Mohri D, Kumoi T. Recon­ Eisele DW, Richtsmeier WJ, Graybeard JC, Koch WM, sideration on the hyoid syndrome. Otolaryngol Head Neck Zinreich SJ. Three-dimensional models for head and neck Surg 1994;110:324-329. tumor treatment planning. Laryngoscope 1994; 104:433- The authors present four cases, illustrated with three CT 439. images and one xeroradiograph. Each case (and figure) Plastic mandibular models generated by three-dimen­ purports to show an abnormally prominent greater cornu sional computed tomography (CT) reconstruction and of the hyoid. All patients had the offending greater cornu dental impression type models of the maxilla were each removed, with relief of symptoms. Nonetheless, "hyoid evaluated for usefulness for the head and neck surgeon. greater cornu" syndrome, caused by irritation of the sym­ The first type was expensive and technologically intensive pathetic plexus around carotid artery or sinus branch of and the second type was simple but limited. Both models glossopharyngeal nerve, remains unconvincing.D JLW were valuable in certain clinical situations and both had Deutsch ES, Milmoe G. Stridor in an adolescent: an un­ disadvantages of cost, time, and possible inaccuracies usual symptom. Otolaryngol Head Neck Surg 1994; 110: caused by image artifacts.DRBL 330-332. New-onset stridor in adolescents is rare. A 14-year-old with stridor had a tracheal papilloma diagnosed on MR (one sagittal image), fiberoptic bronchoscopy, and frozen­ section pathology. The final pathologic diagnosis was mu­ coepidermoid carcinoma of the trachea, which is rare, and occurs most frequently in teenagers and young adults. Another item for your "laundry list."D JLW 1598 ANNOTATED BIBLIOGRAPHY AJNR: 15, September 1994

Goepfert H, Callender DL. Differentiated thyroid cancer­ Lee N, Radtke RA , Gray L, et al. Neuronal migration dis­ papillary and follicular carcinomas. Am J Otolaryngol orders: positron emission tomography correlations. Ann 1994;15:167-179. Neural 1994;35:290 -297. More than 90% of thyroid carcinomas are well-differen­ The extent of neuronal migration disease is important in tiated. This is a thorough review emphasizing the patho­ surgical planning for epilepsy patients because the best genesis, diagnosis, and treatment of these lesions. Much of prognosis is seen when the lesion and epileptogenic region the information in this thorough review is highly pertinent are completely removed. lnterictal FOG-positron emission to contemporary head and neck radiology .OJDS tomography findings were correlated with MR findings in 17 epileptic patients with neuronal migration disorders. Fifteen patients with abnormal MR findings had focal hypometa­ bolic regions in nine cases and a unique finding of dis­ placed metabolic activity of normal gray matter in six Ophthalmologic Radiology cases. Three of the nonhypometabolic cases showed larger Zagelbaum BM, Hersh PS, Donnenfeld ED, Perry HD, lesions on positron emission tomography than on MR.ONA Hochman MA . Occasional notes: ocular trauma in major­ Renowden SA, Squier M. Unusual magnetic resonance league baseball players. N Eng/ J Med 1994;330: 1022- and neuropathological findings in hemimegalencephaly: 1023. report of a case following hemispherectomy. Dev Med This (unintentionally?) amusing study presents impor­ Child Neural 1994;36:357-369. tant findings. A 1-year prospective study found 24 eye Neuropathologic tissue obtained at the time of hemi­ in 21 major-league players, or 1.9 eye injuries per spherectomy from a 15-year-old with hemimegalen­ 100,000 "player-innings." Batted balls, eye-rubbing, for­ cephaly and persisting is correlated with MR im­ eign bodies, and the shortstop's knee accounted for most aging alteration.OJAB of the injuries. Of the 21 players, only one wore safety glasses! These players' potential to influence eye-protec­ Cohen M, Roessmann U. In utero brain damage: relation­ tion habits by setting a (good) example is (as it were) ship of gestational age to pathological consequences. overlooked.DJLW Dev Med Child Neural 1994;36:263-170. Two episodes of intrauterine asphyxia are correlated with neuropathologic findings and with a review of the literature. Although intensity and duration of asphyxia is difficult to characterize, insults occurring before 24 weeks Nose, Paranasal Sinuses, Face, and Oral of gestation had bilateral pallidal necrosis as a common Cavity feature, while an insult between 26 and 34 weeks of ges­ tation was commonly associated with thalamic and brain­ Ferguson BJ. Fibrous dysplasia of the paranasal sinuses. stem necrosis. No images are included.OJAB Am J Otolaryngo/1994;15:227-230. Fibrous dysplasia involving the paranasal sinuses is a Moller JR, Trapp BD, Schiffmann R, et al. Childhood ataxia rare subset of craniofacial fibrous dysplasia. Medullary with diffuse central nervous system hypomyelination. bone is replaced by structurally unsound fibroosseous Ann Neuro/1994;35:331-340. tissue. This may result in recurrent infections, mucocele Four patients demonstrate diffuse white matter disease formation, nasal airway obstruction, and facial pain. An of the and parts of the cerebellum on CT and MR excellent and well-illustrated review presenting two origi­ examinations with minimal clinical findings. Progressive nal cases clearly defined with high quality CT scans.O JDS clinical was identified without abnormali­ ties found in the evaluation for known metabolic and de­ generative diseases. This progression was not reflected on the MR or CT examinations. MR spectroscopy demon­ strated marked decrease in the N-acetylaspartic acid, cho­ Pediatric Neuroradiology line, and creatine of the white matter relative to gray mat­ ter. This appeared to be specific in this distinct clinical Torres CT, Rebsamen S, Silber JH, et al. Surveillance pathological syndrome, because it has not been previously scanning of children with medulloblastoma. N Eng/ J Med reported in other white matter diseases.ONA 1994;330:892-895. This retrospective study compared "surveillance scan­ ning" (CT, MR) to history and physical examination for Phakomatoses detecting tumor recurrence after therapy for medulloblas­ North K, Joy P, Yuille D, et al. Specific learning disability toma (posterior fossa primitive neuroectodermal tumor). in children with neurofibromatosis type 1: significance of Of 86 children, four (clinically asymptomatic) recurrences MRI abnormalities. Neurology 1994;44:878-883. were detected by scans, and 19 recurrences were detected An interesting paper. Patients with neurofibromatosis clinically. One problem with the study is that MR , intro­ type 1 and focal areas of high intensity on T2-weighted duced during the study period ( 1980-1991), might have MR had a much higher risk for impaired academic detected disease missed on CT. The authors acknowledge achievement than patients with neurofibromatosis type 1 this. Their conclusion, that surveillance scanning has lim­ who did not have the T2 changes. Furthermore, the fre­ ited clinical value, is debatable, because they studied a quency of learning disability in the neurofibromatosis pop­ tumor for which cure after recurrence is, in their words, ulation was much higher than that expected for the general "rare."OJLW population .DSMW AJNR: 15, September 1994 ANNOTATED BIBLIOGRAPHY 1599

Seizure Disorders Garcia PA, Laxer KD, van der Grond J , et al. Phosphorus magnetic resonance spectroscopic imaging in patients Cendes F, Andermann F, Preul MC, Arnold DL. Lateraliza­ with frontal lobe epilepsy. Ann 1'/euro/1994;35:217-221. tion of temporal lobe epilepsy based on regional meta­ Phosphorus MR single-photon emission CT was used in bolic abnormalities in proton magnetic resonance spec­ eight patients with frontal lobe epil epsy determined by ictal troscopic images. Ann l'leurol 1994;35:211-216. electroencephalogram recordings and with normal MR Lateralization of temporal lobe epilepsy of 10 patients findings. Within the epileptogenic frontal lobe the mean who had surgical treatment of medically intractable epi­ pH was significantly increased in five patients compared lepsy was compared with findings in 5 healthy control with the contralateral frontal lobe and with control sub­ subjects using the reduced N-acetylaspartate-to-creatine jects. The phosphomonoester levels were decreased ratio. This ratio showed agreement with the side of clinical­ asymmetrically, correctly lateralizing the frontal epil epto­ electroencephalogram lateralization and MR abnormalities genic foci in seven of eight patients. The mean inorganic in all cases. One patient had no MR abnormalities but phosphate levels failed to provide lateralizing informa­ showed MR spectroscopy abnormalities confirmed patho­ tion, because they were not consistently increased within logically as mild hippocampal sclerosis, suggesting that the epileptogenic focus as in patients with temporal lobe epi­ MR spectroscopy may be able to show neuronal loss in lepsy.DNA these patients with a greater sensitivity than MR. D NA Spine Cook MJ. Mesial temporal sclerosis and volumetric inves­ tigations. Acta l'leurol Scand Suppl 1994;89 (152):109- Ditunno JF, Forma CS. Current concepts: chronic spinal 114. cord injury. 1'1 Eng/ J fVled 1994;330:550-557. This paper, in an Acta l'leurologica volume devoted to The authors of this interesting paper are rehabilitation epilepsy surgery, regards the value of volumetric MR ex­ physicians. They discuss pathophysiology, manifesta­ amination of the mesial temporal lobe structures in tions, and management of complications encountered both in the second year and more than 30 years after patients with clinical temporal lobe seizures. Numerous injury. Psychosocial issues include employ­ papers on the neurophysiology, value of subdural ment, sexual function, parenthood, aging, and life satis­ electrodes, magnetic source imaging, MR, and functional faction. These are important clinical correlates of condi­ changes including positron emission tomography in tions neuroradiologists often diagnose without pausing to patients with temporal lobe problems are discussed in consider the ramifications.D JLW this volume.DSMW Zimmerman GA, Weingarten K, Lavyne MH . Symptomatic Kitchen ND, Thomas DGT, Shorvon SD, Fish DR, Stevens lumbar epidural varices: report of two cases. J 1'/eurosurg JM. Volumetric analysis of epilepsy surgery resections 1994;80:914-918. using high resolution magnetic imaging: technical report. Describes a rare cause of back pain with good imaging BrJ l'leurosurg 1993;7:651-656. findings, color operative photos, and discussion. I had A technique for obtaining accurate baseline postopera­ never heard of this entity until I encountered my first case tive examinations with a volumetric MR technique was about 3 years ago.DADE used in 25 patients. This method lends itself to further work to' evaluate the efficacy of lesionectomy versus an en-bloc Barnsley L, Lord SM, Wallis BJ, Bogduk N. Lack of effect resection as related to the volume of brain removed and of intraarticular corticosteroids for chronic pain in the the long-term functional follow-up .DNA cervical zygoapophyseal joints. 1'1 Eng/ J fVled 1994;330: 1047-1050. Jack CR, Mullan BP, Sharbrough FW, et al. Intractable Patients with chronic neck pain after whiplash under­ nonlesional epilepsy of temporal lobe origin: lateralization went a therapeutic trial injection of local anesthetic into by interictal SPECT versus MRI. Neurology 1994;829- dorsal rami supplying cervical zygoapophyseal joints. If 836. their pain diminished, they were randomized into a group that received bupivacaine or a group that received beta­ The authors found that MR of the temporal lobe is more methasone (local anesthetic or steroids introduced into accurate than single-photon emission CT in providing ac­ zygoapophyseal joints under fluoroscopic guidance). Du­ curate lateralization. More specifically, hippocam­ ration of pain relief was 3.5 days for bupivacaine, 3.0 days pal volume measurements correctly lateralized seizures in for betamethasone. The authors conclude that intraarticu­ 86% of cases, whereas single-photon emission CT cor­ lar steroid therapy is not worth the risk and radiation ex­ rectly lateralized seizures in 45% of cases.D SMW posure. The study is nicely designed, the discussion is thoughtful and thought-provoking.DJLW Jackson GD , Connelly A, Cross JH, Gordon I, Gadian DG . Functional magnetic resonance imaging of focal seizures. Carette S. Whiplash injury and chronic neck pain. 1'1 Eng/ l'leurology 1994;44:850-856. J fVled 1994;330: 1083-1084. An interesting case report of a patient with seizures This accompanying editorial provides some interesting studied with a conventional 1.5T MR system with a flash statistics on "late whiplash syndrome." The author firmly sequence. The images acquired every 10 seconds in states that there is now enough evidence that steroid in­ blocks of 60 images were obtained during clinical seizures jection into apophyseal joints is ineffective. He believes the and showed sequential activation associated with specific practice should be stopped, perhaps by discontinuing gyri.DSMW third-party reimbursement. An unexpected proposal! D JLW 1600 A NNOTATED BIBLIOGRAPHY AJNR: 15, September 1994

Stroke Spingarn AT, Selesnick SH , Minick CR. Inner ear cho­ lesteatoma: an embryologic aberration. Otolaryngol Head J ansen C, Ramos LMP, van Heesewijk JPM, Moll FL, van Neck Surg 1994; 110:333-337. Gijn J , A ckerstaff RGA. Impact of microembolism and This supposed primary cochlear cholesteatoma caused hemodynamic changes in the brain during carotid endar­ tinnitus, hearing loss, dysequilibrium, and ear pain. The terectomy. Stroke 1994;25:992-997. MR (included) showed intense enhancement of the co­ Pre- and postoperative CT or MR was monitored in pa­ chlea, vestibule, semicircular canal, and fundus of the tients undergoing carotid endarterectomy, with monitoring internal auditory canal. The CT (included) showed erosion of the endarterectom y with transcranial Doppler. There of the otic capsule. (Close examination of the MR suggests was a significant correlation between the number of em­ erosion of the otic capsule.) This wordy case report dis­ bolic signals during surgica l dissection of the carotid artery cusses hypotheses on the causes of primary cholesteato­ and occurrence of intraoperative infarcts. Two MR figures. mas and epidermoids: metaplasia, aberrant differentiation O JSR in utero, aberrant migration, aberrant inclusion of epithe­ Grasso MG, Pantano P, Ri cci M , et al. Mesial temporal lium. The authors admit their case remains puzzling. Per­ cortex hypoperfusion is associated with depression in haps this was a middle ear cholesteatoma after all? Per­ subcortical stroke. Stroke 1994;254:980-985. haps the pathologic diagnosis is inaccurate?O JLW Fifteen patients with a single subcortical lesion were evaluated for depression as well as with single-photon Kavanaugh KT. Applications of image-directed robotics emission CT using 99mTc hexam ethylpropyleneamine in otolaryngologic surgery. Laryngoscope 1994; 104:283- oxime. A number of flow values were lower in the de­ 292. pressed patients than the nondepressed, only in the mesial Using image-directed robotics, antrostomies were per­ temporal cortex of the affected hemisphere . Authors sug­ formed on five human temporal bone specimens. The gest the temporal lobe hyperperfusion reflects dysfunction antrum was reached in all bones. The dura, horizontal of the limbic system , which may underlie depressive phe­ canal, sigmoid sinus, and fa cial nerve were not violated in nom enology. Two color single-photon emission CT any specimen. The average absolute error in bone removal figures .DJ SR was 0.88 mm. The use of a robotic arm with tighter joints and redundant position checking should overcome most of Gideon P, Sperling B , Arlien-Soborg P, Olsen TS, these problems.DRBL Henriksen 0 . Long-term follow-up of cerebral infarction patients with proton magnetic resonance spectroscopy. Moreano EH , Paparella MM, Zelterman D, Goycoolea MV. Stroke 1994;25:967-973. Prevalence of facial canal dehiscence and of persistent Six patients with ischemic stroke were evaluated in the stapedial artery in the human middle ear: a report of 1000 acute stage to the chronic stage with proton MR spectros­ temporal bones. Laryngoscope 1994; 104:309- 320. copy. No clear correlation was found between the level of A total of 1 000 temporal bones were examined to study N-acetylaspartate or lactate in the acute stage of stroke the prevalence of facial canal dehiscence and persistent and the clinical outcome. However, the study group is too stapedial artery. At least one facial canal dehiscence was sm all to draw any definite conclusions regarding the prog­ present in 56% of the temporal bones most commonly nostic information of spectroscopy. O JSR near the oval window. There was a 76% prevalence of bilaterality of this finding. Microdehiscence of the facial canal was present in 75% of specimens with a 40% bilat­ Temporal Bone erality. Persistent stapedial artery was present in 0.48% of the specimens.DRBL Katsarkas A . Dizziness in aging: a retrospective study of 1194 cases. Otolaryngol Head Neck Surg 1994; 110:296- 30 1. This is a frustratingly vague retrospective study of 1194 patients who were 70 years or older when first seen at a Trauma "dizzyness clinic." Odd results: 2 1% of patients remained Young WB, Silberstein SD. Imaging and electrophysi­ "undiagnosed;" 39% were "strongly suspected" of having ologic testing in mild head injury. Semin Neuro/1994;14: paroxysm al positional vertigo. "Cardiovascular" causes 46. are included with the 8.7% with "nonvestibular, non-neu­ The efficacy of plain skull radiographs, CT, and MR after rologic" disease, but another 6.3% were diagnosed with mild head injury is reviewed with an extensive list of ref­ "." This distinction is not ex ­ erences. Strategies for obtaining imaging studies relative plained. Seventeen patients had tumors: "most" were to Glasgow Coma Scale, clinical course, and type of injury acoustic neurom as or m eningiomas. It is unclear when are reviewed.D JAB (and which ) imaging studies were used. The conclusion restates the introduction. What has been learned?OJLW