The value of qualitative and quantitative assessment of lesion to cerebral cortex signal ratio on double inversion recovery sequence in the differentiation of demyelinating plaques from non-specific T2 hyperintensities.

OBJECTIVES: To assess the usefulness of the visual assessment and to determine diagnostic value of the lesion-to-cerebral cortex signal ratio (LCSR) measurement in the differentiation of demyelinating plaques and non-specific T2 hyperintensities on double inversion recovery (DIR) sequence. MATERIAL AND METHODS: DIR and fluid-attenuated inversion recovery (FLAIR) sequences of 25 clinically diagnosed multiple sclerosis (MS) patients and 25 non-MS patients with non-specific T2-hyperintense lesions were evaluated visually and LCSRs were measured by two observers independently. RESULTS: On DIR sequence, the calculated mean LCSR ± SD for demyelinating plaques and non-specific T2-hyperintense lesions were 1.60 ± 0.26 and 0.75 ± 0.19 for observer1, and 1.61 ± 0.27 and 0.74 ± 0.19 for observer2. LCSRs of demyelinating plaques were significantly higher than other non-specific T2-hyperintense lesions on DIR sequence. By using the visual assessment demyelinating plaques were differentiated from non-specific T2-hyperintensities with 92.8 % sensitivity, 97.5 % specificity and 95.1 % accuracy for observer1 and 92.8 % sensitivity, 95 % specificity and 93.9 % accuracy for observer2. CONCLUSION: Visual assessment and LCSR measurement on DIR sequence seems to be useful for differentiating demyelinating MS plaques from supratentorial non-specific T2 hyperintensities. This feature can be used for diagnosis of MS particularly in patients with only supratentorial T2-hyperintense lesions who are categorized as radiologically possible MS. KEY POINTS: • Demyelinating plaques and non-specific T2-hyperintensities have different SI on DIR images. • These differences can be assessed by LCSR measurement or visual assessment. • There is an excellent inter-observer agreement for both methods. • This feature can be used in radiologically possible MS cases.

Brain herniations into the dural venous sinus or calvarium: MRI findings, possible causes and clinical significance.

OBJECTIVES: To determine frequency, imaging features and clinical significance of herniations of brain parenchyma into dural venous sinuses (DVS) and/or calvarium found on MRI. METHODS: A total of 6160 brain MRI examinations containing at least one high-resolution T1- or T2-weighted sequence were retrospectively evaluated to determine the presence of incidental brain herniations into the DVS or calvarium. MRI sequences available for review were evaluated according to their capability to demonstrate these herniations. Patients' symptoms and clinical findings were recorded. RESULTS: Twenty-one (0.32 %) brain parenchyma herniations into the DVS (n = 18) or calvarium (n = 3) in 20 patients were detected. The most common locations of the herniations were the transverse sinuses (n = 13) and those involving inferior gyrus of the temporal lobe (n = 9). High-resolution T1- and T2-weighted sequences were equally useful in the detection of these brain herniations. According to clinical symptoms, brain herniations were considered to be incidental but headaches were present in nine patients. CONCLUSION: Brain herniations with surrounding cerebrospinal fluid (CSF) into the DVS and/or calvarium are incidental findings and not proven to be associated with any symptoms. Although rare, these herniations are more common than previously recognized and should not be confused with arachnoid granulations, clots or tumours. KEY POINTS: • Brain herniations into the DVS are more common than previously assumed. • The most frequent locations are the transverse sinus. • These herniations are incidental findings. • The relationship between brain herniation into DVS and headache is uncertain. • High-resolution MR sequences are most useful in detection of brain herniations.

Normal anatomical features and variations of the vertebrobasilar circulation and its branches: an analysis with 64-detector row CT and 3T MR angiographies.

PURPOSE: To determine the normal anatomical features and variations of the vertebrobasilar circulation and its branches in patients who underwent multidetector computed tomography (CT) or magnetic resonance (MR) angiographies of the brain. METHODS: 135 patients (male, 83 and female, 52; mean age, 50.1 years) who underwent CT (n = 71) or MR (n = 64) angiographies of the vertebrobasilar vasculature for various reasons were analyzed retrospectively. The right and left distal vertebral arteries (VAs), posterior inferior cerebellar arteries (PICAs), anterior inferior cerebellar arteries (AICAs), superior cerebellar arteries (SCAs), posterior cerebral arteries (PCAs), and posterior communicating arteries (PCoAs) were analyzed individually. RESULTS: In 24.4% of the cases (33/135) right PICA, in 19.3% of the cases (26/135) left PICA, in 17.8% of the cases (24/135) right AICA, and in 18.5% of the cases (25/135) left AICA were absent. In cases without PICA or AICA, there was a statistically significant, moderately or well-developed AICA or PICA on the same side, respectively (P < 0.001). The most common variation was isolated absence of right PICA and was seen in 17.8% of the cases. CONCLUSIONS: The anatomic features of the branches of the vertebrobasilar circulation may be different from well-known normal anatomy. CT and MR angiographies allow a precise and detailed evaluation of vertebrobasilar circulation.

P300 auditory event-related potentials in children with obesity: is childhood obesity related to impairment in cognitive functions?

OBJECTIVE: To investigate alterations in P300 auditory event-related potentials in children with obesity to detect changes in cognitive functions. METHOD: A total of 50 children with obesity and 23 age- and sex-matched healthy control subjects were included in the study. Laboratory tests were performed to detect dislipidemia and insulin resistance (IR). The latencies and amplitudes of P300 waves were measured in healthy and obese subjects with or without IR. The oddball paradigm was used in recordings of P300 auditory event-related potentials. RESULTS: A significant difference was observed between groups regarding latency and amplitude of P300 component obtained from central (Cz) electrode. The grand means of P300 latency were longer, and amplitude decreased significantly in obese group compared to that of healthy controls. When the obese group was divided into two different subgroups, those with IR and without IR, the grand means of P300 latency were longer and the amplitude decreased significantly in subjects with IR compared to those without IR. CONCLUSION: Both decreased amplitude and prolonged latency of P300 are associated with IR in children with obesity, which shows the impairment of neural activity associated with sensory and cognitive information processing in these children. Further studies are necessary to strengthen the current findings and to determine the exact mechanism of cognitive impairment in obese children.

Can triptans safely be used for airplane headache?

A few cases of airplane headache (AH) have been reported in the literature. Treatment strategies of AHs are also controversial. We followed-up five patients with AH. They were symptom-free during the daytime. Their physical, neurological, and ear-nose-throat examinations were all normal. Blood chemistries, cerebral magnetic resonance imaging, cerebral magnetic resonance imaging angiography, and paranasal sinus tomography studies of the patients were also normal. We preferred triptans because of the possible effect on the mechanism of AH. Patients were recommended to use single-dose of their drugs half an hour prior to flights. All of the patients had a good response to single dose triptan treatment and became headache-free during flights. This is the first study which puts forward the usefulness of the triptans as a safe treatment choice for airplane AH.

Electrophysiological assessment of the autonomic nervous system in male patients with acromegaly.

BACKGROUND/AIMS: We aimed to electrophysiologically evaluate the autonomic function in acromegalic patients using sympathetic skin response (SSR) as a reflection of the sympathetic sudomotor activity and RR interval variation (RRIV) as an indicator of the cardiovagal autonomic function. METHODS: The study group consisted of 18 male acromegalics, and the control group was composed of 18 age- and sex-matched healthy subjects. Participants underwent SSR and RRIV tests. Beginning latencies and amplitudes of the median and tibial SSRs were compared among the groups. The RRIV values recorded at rest and during hyperventilation were compared among the patients and controls. RESULTS: Latencies of SSRs recorded from the palms (median) and soles (tibial) of acromegalics were significantly longer than in healthy subjects (p = 0.004, p < 0.001). The amplitude of SSR recorded from the sole (tibial) was significantly decreased (p = 0.028). The RRIVs obtained from acromegalics at rest and during hyperventilation were significantly decreased compared with those of controls (p < 0.001). The RRIVs obtained from controls prolonged significantly during hyperventilation (p < 0.001); however, in the acromegaly group, hyperventilation did not cause a significant change in RRIV (p = 0.983). CONCLUSIONS: The present study suggests that an autonomic dysfunction exists in patients with acromegaly. Dysautonomia in acromegalics may be documented by means of SSR and RRIV.

Cerebral venous thrombosis presenting with subarachnoid hemorrhage after spinal anesthesia.

A 22-year-old male had a meniscopathy operation using spinal anesthesia. After the operation, the patient reported a throbbing headache. His brain computed tomography (CT) showed subarachnoid hemorrhage (SAH) and hyperdense dural venous sinuses suspicious for thrombosis. Filling defects were observed in the superior sagittal and right transverse sinuses on the contrast-enhanced magnetic resonance images. The patient was diagnosed with cerebral venous sinus thrombosis (CVST). On the tenth day of his admission, his clinical findings progressed and heparin therapy was initiated after resorption of hemorrhage was observed in a second non-contrast CT scan. The patient developed decreased consciousness the day after heparin administration. A subsequent brain CT revealed intraparenchymal hemorrhage in the right anteroinferior frontal region. Heparin therapy was discontinued, and anti-edema therapy was started. The presentation of CVST with SAH is a rare condition. Furthermore, development of CVST after spinal anesthesia is very rare. In this case, CVST developed after spinal anesthesia, and its first clinical presentation was SAH. To our knowledge, this is the first case CVST presenting with SAH after spinal anesthesia.

Acute lymphoblastic leukemia presenting with oculomotor nerve palsy.

A 48-year-old man presented with left ptosis and double vision. Laboratory test findings indicated acute lymphoblastic leukemia (ALL). Lymphoblastic infiltration of both cavernous sinuses was observed on pituitary gland magnetic resonance imaging. Leukemias may present by many clinical conditions, but isolated cranial nerve palsy is very rare. To our knowledge, this is the first case of ALL presenting with oculomotor nerve palsy. Clinicians should consider oculomotor nerve palsy as the first ALL indication.

Superficial radial neuropathy and brachioradial motor nerve palsy associated with proximal radius osteochondroma.

The cutaneous branch of the radial nerve (superficial radial nerve, SRN) might be compressed or injured at various anatomical sites along its course in the forearm. Compression of the SRN occurring at the proximal third of the forearm is unusual. A 22-year-old man was admitted with pain and paraesthesia over the lateral aspect of his right wrist and thumb and pain at the elbow for six months. In electrodiagnostic testing, a sensory nerve action potential from the right SRN could not be recorded, while it was normal on the left. In a needle electromyography study, denervation potentials have been seen in the right brachioradial muscle and a decrease in interference pattern signals was also found. An exophytic lesion of the proximal radius was observed in radiographs. Computed tomography evaluation revealed an osteochondroma of the proximal radius. Neuropathies of the SRN and the brachioradial motor branch of the radial nerve are thought to be associated with proximal radial osteochondroma.

Pattern visual evoked potentials in the assessment of objective visual acuity in amblyopic children.

The aim of this study was to determine the value of pattern visual evoked potentials (PVEP) to five consecutive check size patterns in the assessment of visual acuity (VA) in children. One hundred unilateral amblyopic (study group) and 90 healthy children with best-corrected visual acuity (BCVA) of 1.0 (control group) were planned to be included. PVEP responses to five consecutive check sizes (2 degrees , 1 degrees , 30', 15', and 7') which are assumed to correspond to VAs of 0.1, 0.2, 0.4, 0.7 and 1.0 Snellen lines were recorded in both groups. Eighty-five children in the study group (85.0%) and 74 children in the control group (82.2%) who cooperated well with PVEP testing were included. Normal values for latency, amplitude, and normalized interocular amplitude/latency difference in each check size were defined in the control group. PVEP-estimated VA (PVEP-VA) in the amblyopic eye was defined by the normal PVEP responses to the smallest check size associated with normal interocular difference from the non-amblyopic eye, and was considered predictive if it is within +/-1 Snellen line (1 decimal) discrepancy with BCVA in that eye. Mean age was 9.7 +/- 1.9 and 9.9 +/- 2.2 years in the study and the control groups, respectively. LogMAR (logarithm of minimum angle of resolution) Snellen acuity was well correlated with the logMAR PVEP-VA (r = 0.525, P < 0.001) in the study group. The Snellen line discrepancy between BCVA and PVEP-VA was within +/-1 Snellen line in 57.6% of the eyes. PVEP to five consecutive check sizes may predict objective VA in amblyopic children.

Electrophysiological findings in patients with adult tethered cord syndrome.

AIM: This study was planned for detailed evaluation of electrophysiological findings in patients with adult TCS. MATERIAL AND METHODS: Patients were retrospectively assessed for clinical, radiological and electrophysiological data between 1999 and 2008. Tibial somatosensorial evoked potentials, needle electromyography, nerve conduction studies and late responses (H reflex and F response) were studied in thirty (1 female, 29 males) TCS patients diagnosed by lumbar magnetic resonance imaging. RESULTS: Tibial somato-sensorial evoked potentials cortical response latency was abnormal in 18 (60%) patients. Needle electromyography revealed chronic neurogenic involvement in 13 (43.3%) patients. In nerve conduction studies, motor unit action potential amplitudes were reduced in 5 (16.6%) patients and H reflexes were abnormal in 13 (43.3%) patients. CONCLUSION: Different electrophysiological abnormalities may be seen in patients with adult TCS. Our results indicated that tibial SEP abnormalities are most sensitive electrophysiological finding in patients with adult TCS. Patients with TCS should undergo electrophysiological examinations whether they have subjective or objective complaints. These examinations should evaluate different systems and treatment planning should be done with the data obtained.

Reversible cerebral vasoconstriction syndrome: case report.

A 28-year-old woman had thunderclap headache (TCH), after 7 days she had left hemiparesis. She had a history of oral contraceptive and citalopram medications. Brain magnetic resonance (MR) angiography demonstrated multiple stenotic segments. Digital subtraction angiography (DSA) showed multiple segments of narrowing in vessel calibre. Two probable diagnoses performed; primary angiitis of the central nervous system and reversible cerebral vasoconstriction syndrome (RCVS). Because of clinical characteristics and normal cerebrospinal fluid findings she was set on medication for probable RCVS. Follow-up MR angiography after 4 weeks and DSA after 7 weeks demonstrated improvement in vessel calibre. Thus, diagnosis RCVS was established. Diagnosis and management of TCH contain many potential difficulties. Clinicians should consider the imaging of cerebral arteries, even if computed tomography scan and lumbar puncture are normal in TCH. Potential precipitating factors and triggers should also be known and avoided.

Decreased cerebral vasomotor reactivity in patients with obstructive sleep apnea syndrome.

OBJECTIVE: In obstructive sleep apnea syndrome (OSAS), any of the activated neural, vascular, hemodynamic, metabolic, inflammatory, and thrombotic mechanisms may be related to increased cerebrovascular disease and risk of death; however, the possible pathophysiological process between obstructive sleep apnea syndrome and stroke has not been clearly explained. We hypothesize that alterations in vasomotor reactivity in patients may be responsible for their altered cerebral blood flow, and may contribute to the increased risk of ischemic stroke. METHODS: A total of 30 untreated patients with severe obstructive sleep apnea and 26 control subjects were included in the study. The mean blood flow velocity and breath holding index were measured in middle cerebral artery bilaterally in both patient and control groups by using transcranial Doppler ultrasound. We compared the values between two groups. RESULTS: The mean blood flow velocity and breath holding indexes were significantly decreased in the patient group when compared with the control group. There were no correlations between cerebral hemodynamic parameters and polysomnographic findings in patients. CONCLUSION: Our findings suggest that there was a deteriorated vasodilator response to hypercapnia in patients with OSAS. This deterioration may stem from chemoreceptors or endothelial damages that lead to vascular relaxation and vasodilatation in cerebrovascular circulation. This impaired cerebral vascular regulation may contribute to the increased risk of stroke in patients with OSAS.

Reduced breath holding index in patients with chronic migraine.

Migraine is a neurovascular disorder characterized by autonomic nervous system dysfunction and severe headache attacks. Studies have shown that changes in the intracranial vessels during migraine have an important role in the pathophysiology. Many studies have been conducted on the increased risk of stroke in patients with migraine, but insufficient data are available on the mechanism underlying the increase. This study aimed to evaluate basal cerebral blood flow velocity and vasomotor reactivity in patients with chronic migraine. We evaluated 38 patients with chronic migraine. Three of them were excluded because they had auras and four of them were excluded because of their use of medication that can affect cerebral blood flow velocity and breath holding index (beta or calcium channel blockers). Our study population consisted of 31 patients with chronic migraine without aura and 29 age- and gender-matched healthy individuals who were not taking any medication. The mean blood flow velocity and breath holding index were measured on both sides from the middle cerebral artery and posterior cerebral artery, with temporal window insonation. The breath holding index for middle cerebral artery and posterior cerebral artery was significantly lower in the migraine group compared to that of the control group (p < 0.05).The vasomotor reactivity indicates the dilatation potential of a vessel, and it is closely related to autoregulation. According to our results, the vasodilator response of cerebral arterioles to hypercapnia was lower in patients with chronic migraine. These findings showed the existence of impairments in the harmonic cerebral hemodynamic mechanisms in patients with chronic migraine. This finding also supports the existing idea of an increased risk of stroke in patients with chronic migraine due to impaired vasomotor reactivity.

Breath-holding spells may be associated with maturational delay in myelination of brain stem.

PURPOSE: To evaluate possible contribution of maturational delay of brain stem in the etiology of breath-holding spells in children using brain stem auditory evoked potentials. METHODS: The study group included children who experienced breath-holding spells. The control group consisted of healthy age- and sex-matched children. Age, gender, type and frequency of spell, hemoglobin, and ferritin levels in study group and brain stem auditory evoked potentials results in both groups were recorded. Study group was statistically compared with control group for brain stem auditory evoked potentials. RESULTS: The mean age of study and control groups was 26.3 ± 14.6 and 28.9 ± 13.9 months, respectively. The III-V and I-V interpeak latencies were significantly prolonged in the study group compared with the control group (2.07 ± 0.2 milliseconds; 1.92 ± 0.13 milliseconds and 4.00 ± 0.27 milliseconds; 3.83 ± 0.19 milliseconds; P = 0.009 and P = 0.03, respectively). At the same time, III-V and I-V interpeak latencies of patients without anemia in the study group compared with those of control group were significantly prolonged (2.09 ± 0.24 milliseconds; 1.92 ± 0.13 milliseconds and 4.04 ± 0.28 milliseconds; 3.83 ± 0.19 milliseconds; P = 0.007 and P = 0.01, respectively). CONCLUSIONS: Our results consider that maturational delay in myelination of brain stem may have a role in the etiology of breath-holding spells in children.

Color vision versus pattern visual evoked potentials in the assessment of subclinical optic pathway involvement in multiple sclerosis.

BACKGROUND: Optic pathway involvement in multiple sclerosis is frequently the initial sign in the disease process. In most clinical applications, pattern visual evoked potential (PVEP) is used in the assessment of optic pathway involvement. OBJECTIVE: To question the value of PVEP against color vision assessment in the diagnosis of subclinical optic pathway involvement. MATERIALS AND METHODS: This prospective, cross-sectional study included 20 multiple sclerosis patients without a history of optic neuritis, and 20 healthy control subjects. Farnsworth-Munsell (FM) 100-Hue testing and PVEPs to 60-min arc and 15-min arc checks by using Roland-Consult RetiScan® system were performed. P 100 amplitude, P 100 latency in PVEP and total error scores (TES) in FM 100-Hue test were assessed. RESULTS: Expanded Disability Status Scale score and the time from diagnosis were 2.21 ± 2.53 (ranging from 0 to 7) and 4.1 ± 4.4 years. MS group showed significantly delayed P 100 latency for both checks (P < 0.001). Similarly, MS patients had significantly increased total error scores (TES) in FM-100 Hue (P < 0.001). The correlations between TESs and PVEP amplitudes / latencies were insignificant for both checks (P > 0.05 for all). 14 MS patients (70%) had an increased TESs in FM-100 Hue, 11 (55%) MS patients had delayed P 100 latency and 9 (45%) had reduced P 100 amplitude. The areas under the ROC curves were 0.944 for FM-100 Hue test, 0.753 for P 100 latency, and 0.173 for P 100 amplitude. CONCLUSIONS: Color vision testing seems to be more sensitive than PVEP in detecting subclinical visual pathway involvement in MS.