Depicting the pterygopalatine ganglion on 3 Tesla magnetic resonance images.

PURPOSE: The pterygopalatine ganglion has yet not been identified on medical images in living humans. The primary aim of this study was to evaluate whether the pterygopalatine ganglion could be identified on 3 T MR imaging. METHODS: This study was performed on medical images of 20 Caucasian subjects on both sides (n = 40 ganglia) with an exploratory design. 3 T MR images were assessed by two physicians for the presence and size of the pterygopalatine ganglion. The distance from the pterygopalatine ganglion to four bony landmarks was registered from fused MR and CT images. In an equivalence analysis, the distances were compared to those obtained in an anatomical cadaveric study serving as historical controls (n = 50). RESULTS: A structure assumed to be the pterygopalatine ganglion was identified on MR images in all patients on both sides by both physicians. The mean size was depth 2.1 ± 0.5 mm, width 4.2 ± 1.1 mm and height 5.1 ± 1.4 mm, which is in accordance with formerly published data. Equivalence of the measurements on MR images and the historical controls was established, suggesting that the structure identified on the MR images is the pterygopalatine ganglion. CONCLUSION: Our findings suggest that the pterygopalatine ganglion can be detected on 3 T MR images. Identification of the pterygopalatine ganglion may be important for image-guided interventions targeting the pterygopalatine ganglion, and has the potential to increase the efficacy, safety and reliability for these treatments.

Pilot study of sphenopalatine injection of onabotulinumtoxinA for the treatment of intractable chronic migraine.

Objective The main objective of this pilot study was to investigate the safety of administering onabotulinumtoxinA towards the sphenopalatine ganglion in 10 patients with intractable chronic migraine with an open, uncontrolled design. We also collected efficacy data to provide an indication as to whether future placebo-controlled studies should be performed. Method In a prospective, open-label, uncontrolled study after one-month baseline, we performed bilateral injections of 25 IU onabotulinumtoxinA (total dose 50 IU) toward the sphenopalatine ganglion in a single outpatient session in 10 patients with intractable migraine with a follow-up of 12 weeks. The primary outcome was adverse events and the main efficacy outcome was frequency of moderate and severe headache days in month 2 post-treatment compared to baseline. Results All 10 patients experienced a total of 25 adverse events. The majority of these were different types of local discomfort in the face and jaw, and none were classified as serious. In an intention-to-treat analysis of the main efficacy outcome, a statistically significant reduction of moderate and severe headache days in baseline versus month 2 was observed (16.3 ± 6.2 days baseline versus 7.6 ± 7.6 days month 2, p = 0.009). Eight out of 10 patients experienced an at least 50% reduction of moderate and severe headache days compared to baseline. Conclusion The result warrants randomised, placebo-controlled studies to establish both safety and efficacy of this potential novel treatment of chronic migraine.

Pilot study of sphenopalatine injection of onabotulinumtoxinA for the treatment of intractable chronic cluster headache.

OBJECTIVE: The main object of this pilot study was to investigate the safety of administering onabotulinumtoxinA (BTA) towards the sphenopalatine ganglion (SPG) in intractable chronic cluster headache. Efficacy data were also collected to provide indication on whether future placebo-controlled studies should be performed. METHOD: In a prospective, open-label, uncontrolled study, we performed a single injection of 25 IU (n = 5) or 50 IU BTA (n = 5) towards the SPG in 10 patients with intractable chronic cluster headache with a follow-up of 24 weeks. The primary outcome was adverse events (AEs) and the main efficacy outcome was attack frequency in weeks 3 and 4 post-treatment. RESULTS: A total of 11 AEs were registered. There was one severe adverse event (SAE): posterior epistaxis. The number of cluster headache attacks (main efficacy outcome) was statistically significantly reduced in the intention-to-treat analysis from 18 ± 12 per week in baseline to 11 ± 14 (p = 0.038) in weeks 3 and 4, and five out of 10 patients had at least 50% reduction of attack frequency compared to baseline. The cluster attack frequency was significantly reduced for five out of six months post-treatment. CONCLUSION: Randomised, placebo-controlled studies are warranted to establish the potential of this possible novel treatment of cluster headache.

Traumatic axonal injury: the prognostic value of lesion load in corpus callosum, brain stem, and thalamus in different magnetic resonance imaging sequences.

The aim of this study was to explore the prognostic value of visible traumatic axonal injury (TAI) loads in different MRI sequences from the early phase after adjusting for established prognostic factors. Likewise, we sought to explore the prognostic role of early apparent diffusion coefficient (ADC) values in normal-appearing corpus callosum. In this prospective study, 128 patients (mean age, 33.9 years; range, 11-69) with moderate (n = 64) and severe traumatic brain injury (TBI) were examined with MRI at a median of 8 days (range, 0-28) postinjury. TAI lesions in fluid-attenuated inversion recovery (FLAIR), diffusion-weighted imaging (DWI), and T2*-weighted gradient echo (T2*GRE) sequences were counted and FLAIR lesion volumes estimated. In patients and 47 healthy controls, mean ADC values were computed in 10 regions of interests in the normal-appearing corpus callosum. Outcome measure was the Glasgow Outcome Scale-Extended (GOS-E) at 12 months. In patients with severe TBI, number of DWI lesions and volume of FLAIR lesions in the corpus callosum, brain stem, and thalamus predicted outcome in analyses with adjustment for age, Glasgow Coma Scale score, and pupillary dilation (odds ratio, 1.3-6.9; p = <0.001-0.017). The addition of Rotterdam CT score and DWI lesions in the corpus callosum yielded the highest R2 (0.24), compared to all other MRI variables, including brain stem lesions. For patients with moderate TBI only the number of cortical contusions (p = 0.089) and Rotterdam CT score (p = 0.065) tended to predict outcome. Numbers of T2*GRE lesions did not affect outcome. Mean ADC values in the normal-appearing corpus callosum did not differ from controls. In conclusion, the loads of visible TAI lesions in the corpus callosum, brain stem, and thalamus in DWI and FLAIR were independent prognostic factors in patients with severe TBI. DWI lesions in the corpus callosum were the most important predictive MRI variable. Interestingly, number of cortical contusions in MRI and CT findings seemed more important for patients with moderate TBI.

A longitudinal MRI study of traumatic axonal injury in patients with moderate and severe traumatic brain injury.

OBJECTIVE: To study the evolution of traumatic axonal injury (TAI) detected by structural MRI in patients with moderate and severe traumatic brain injury (TBI) during the first year and relate findings to outcome. METHODS: 58 patients with TBI (Glasgow Coma Scale score 3-13) were examined with MRI at a median of 7 days, 3 months and 12 months post injury. TAI lesions were evaluated blinded and categorised into three stages based on location: hemispheres, corpus callosum and brainstem. Lesions in T2* weighted gradient echo (GRE), fluid attenuated inversion recovery (FLAIR) and diffusion weighted imaging (DWI) were counted and FLAIR lesion volumes were estimated. Inter-rater reliability score was calculated. Outcome was assessed 12 months post injury using the Glasgow Outcome Scale Extended. RESULTS: In the initial MRI, 31% had brainstem lesions compared with 17% at 3 months (p=0.008). In the FLAIR sequences, number and volumes of lesions were reduced from early to 3 months (p<0.001). In T2*GRE sequences, the number of lesions persisted at 3 months but was reduced at 12 months (p=0.007). The number of lesions in DWI and volume of FLAIR lesions on early MRI predicted worse clinical outcome in adjusted analyses (p<0.05). CONCLUSION: This is the first study to demonstrate and quantify attenuation of non-haemorrhagic TAI lesions on structural MRI during the first 3 months after TBI; most importantly, the disappearance of brainstem lesions. Haemorrhagic TAI lesions attenuate first after 3 months. Only early MRI findings predicted clinical outcome after adjustment for other prognostic factors. Hence valuable clinical information may be missed if MRI is performed too late after TBI.

Clinical characteristics, pain, and disability in relation to alar ligament MRI findings.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To evaluate the association between degree of signal changes in the alar ligaments on MRI with respect to pain and disability. SUMMARY OF BACKGROUND DATA: Conflicting evidence exists whether areas of high-signal intensity in the alar ligaments on MRI are associated with pain and disability. METHODS: A cross-sectional designed study of 173 subjects including a group with persistent whiplash associated disorder (WAD) Grade II after a car accident (n = 59), a group with chronic nontraumatic neck pain (n = 57) and a group without neck pain or previous neck trauma (n = 57). To assess pain and disability, all participants filled in the Brief Pain Inventory (BPI-intensity and BPI-interference), the European Quality of Life (EQ-5D and EQ VAS) and the Hospital Anxiety and Depression Rating Scale (HADS). High-resolution proton-weighted MR images in three planes were evaluated by two experienced neuroradiologists who were blinded to patient history and group allocation. The alar ligaments were evaluated according to a 4-point grading scale; 0 = low-signal intensity throughout the entire cross-section area, 1 = high-signal intensity in one third or less, 2 = high-signal intensity in one third to two thirds, and 3 = high-signal intensity in two thirds or more of the cross-section area. RESULTS: With respect to BPI and HADS, the scores were highest in the WAD group, intermediate in the chronic nontraumatic neck pain group, and lowest among controls. EuroQol scores were lowest in the WAD group, intermediate in the chronic nontraumatic neck pain group, and highest among controls (P < 0.001). There was, however, no significant correlation between the alar ligament changes and measures for pain and disability. CONCLUSION: The previously reported assumption that changes in the alar ligaments detected on MRI are associated with pain and disability is not supported by this study. The diagnostic value and the clinical relevance of MR-detectable areas of high intensity in the alar ligaments remain questionable.

Prevalence and impact of diffuse axonal injury in patients with moderate and severe head injury: a cohort study of early magnetic resonance imaging findings and 1-year outcome.

OBJECT: In this prospective cohort study the authors examined patients with moderate to severe head injuries using MR imaging in the early phase. The objective was to explore the occurrence of diffuse axonal injury (DAI) and determine whether DAI was related to level of consciousness and patient outcome. METHODS: One hundred and fifty-nine patients (age range 5-65 years) with traumatic brain injury, who survived the acute phase, and who had a Glasgow Coma Scale (GCS) score of 3-13 were admitted between October 2004 and August 2008. Of these 159 patients, 106 were examined using MR imaging within 4 weeks postinjury. Patients were classified into 1 of 3 stages of DAI: Stage 1, in which lesions were confined to the lobar white matter; Stage 2, in which there were callosal lesions; and Stage 3, in which lesions occurred in the dorsolateral brainstem. The outcome measure used 12 months postinjury was the Glasgow Outcome Scale-Extended (GOSE). RESULTS: Diffuse axonal injury was detected in 72% of the patients and a combination of DAI and contusions or hematomas was found in 50%. The GCS score was significantly lower in patients with "pure DAI" (median GCS Score 9) than in patients without DAI (median GCS Score 12; p < 0.001). The GCS score was related to outcome only in those patients with DAI (r = 0.47; p = 0.001). Patients with DAI had a median GOSE score of 7, and patients without DAI had a median GOSE score of 8 (p = 0.10). Outcome was better in patients with DAI Stage 1 (median GOSE Score 8) and DAI Stage 2 (median GOSE Score 7.5) than in patients with DAI Stage 3 (median GOSE Score 4; p < 0.001). Thus, in patients without any brainstem injury, there was no difference in good recovery between patients with DAI (67%) and patients without DAI (66%). CONCLUSIONS: Diffuse axonal injury was found in almost three-quarters of the patients with moderate and severe head injury who survived the acute phase. Diffuse axonal injury influenced the level of consciousness, and only in patients with DAI was GCS score related to outcome. Finally, DAI was a negative prognostic sign only when located in the brainstem.

Magnetic resonance imaging assessment of the alar ligaments in whiplash injuries: a case-control study.

STUDY DESIGN: Case-control study. OBJECTIVE: To use high-resolution magnetic resonance imaging (MRI) in assessing signal intensity areas in the alar ligaments. SUMMARY OF BACKGROUND DATA: Conflicting evidence exists whether areas of high signal intensity in the alar ligament on MRI are more frequent in whiplash patients than in noninjured control subjects. METHODS: A case-control designed study of 173 subjects included one group with persistent whiplash associated disorder Grade I-II after a car accident (n = 59), one with chronic nontraumatic neck pain (n = 57) and one group without neck pain or previous neck trauma (n = 57). High-resolution proton-weighted MRI in 3 planes was used. The images were independently evaluated by two experienced neuroradiologists who were blinded to patient history and group allocation. The alar ligaments were evaluated according to a 4-point grading scale; 0 = low signal intensity throughout the entire cross section area, 1 = high signal intensity in one third or less, 2 = high signal intensity in one-third to two thirds, and 3 = high signal intensity in two thirds or more of the cross section area. RESULTS: Alar ligament changes Grade 0 to 3 were seen in all 3 diagnostic groups. Areas of high signal intensity (Grade 2-3) were found in at least one alar ligament in 49% of the patients in the whiplash associated disorder Grade I-II group, in 33% of the chronic neck pain group and in 40% of the control group (chi, P = 0.22). CONCLUSION.: The previously reported assumption that these changes are due to a trauma itself is not supported by this study. The diagnostic value and the clinical relevance of magnetic resonance detectable areas of high intensity in the alar ligaments are questionable.