The empty delta sign

Sensitivity and Specificity of Double-Track Sign in the Detection of Transverse Sinus Stenosis: A Multicenter Retrospective Study

BACKGROUND

Transverse sinus stenosis (TSS) is common among patients with cerebral venous sinus thrombosis. No previous studies have reported on double-track sign detected on axial Gd-enhanced T1WI in TSS. This study aimed to determine the sensitivity and specificity of the double-track sign in the detection of TSS.

METHODS

We retrospectively reviewed medical records of 383 patients with transverse sinus thrombosis (TST) and 30 patients with normal transverse sinus from 5 participating hospitals in china from January 2008 to June 2014. 167 feasible transverse sinuses included in this study were categorized into TSS (n = 76), transverse sinus occlusion (TSO) (n = 52) and transverse sinus normal (TSN) groups (n = 39) according to imaging diagnosis on digital subtraction angiography (DSA) or magnetic resonance venography (MRV). Double-track sign on axial Gd-enhanced T1WI was compared among the three groups. Sensitivity and specificity of double-track sign in detection of TSS were calculated, with final imaging diagnosis of TSS on DSA or MRV as the reference standard.

RESULTS

Of 383 patients with TST recruited over a 6.5-year period, 128 patients were enrolled in the study, 255 patients were excluded because of insufficient clinical data, imaging finding and delay time, and 30 matched patients with normal transverse sinus were enrolled in the control group. Therefore, double-track sign assessment was conducted in 167 available transverse sinuses of 158 patients. Of the 76 sinuses in TSS group, 51 had double-track sign. Of the other 91 sinuses in TSO and TSN groups, 3 had a false-positive double-track sign. Thus, double-track sign on axial Gd-enhanced T1WI was 67.1% (95% CI 55.3-77.2) sensitive and 96.7% (95% CI 89.9-99.1) specific for detection of TSS.

CONCLUSIONS

The double-track sign on axial Gd-enhanced T1WI is highly specific and moderate sensitive for detection of TSS. Nevertheless, it could be a direct sign and might provide an early clue for TSS.

[Noninvasive diagnosis of cerebral venous thrombosis]

OBJECTIVES

Cerebral venous thrombosis (CVT) is an uncommon condition. Its variable, unspecific clinical presentation causes delays in diagnosis. We analyze the validity of different neuroimaging techniques, including CT, MRI, MR angiography, and conventional angiography in the diagnosis of CVT.

MATERIAL AND METHODS

We review the imaging findings of 12 patients with the final diagnosis of CVT. All 12 patients underwent CT as the initial imaging test; all 12 underwent MRI; 11 underwent MR angiography; and 4 underwent conventional angiography. Visualization of the thrombus or filling defects in the affected vessel were considered direct signs of CVT, whereas findings compatible with venous infarction were considered indirect signs.

RESULTS

Of the 12 CT examinations, 4 showed direct signs, 2 indirect signs, and 6 only normal findings. Indirect signs of CVT were seen on follow-up CT in three of the patients with normal initial CT examination. CT failed to show the real extent of the process except in one case in which a cortical vein was affected. MRI detected thrombi in the affected territory in 6 cases; the empty delta sign was seen in 2 and signs of venous infarction in 8. MRI failed to diagnose CVT in one case. MR angiography showed direct signs of CVT in all cases, even without intravenous contrast, and the results were similar to those seen at conventional angiography. More than two locations were affected in 11 patients.

CONCLUSIONS

At CT, indirect signs of CVT are seen, although sometimes not immediately. Direct signs can be so subtle that they can only be interpreted with experience. Furthermore, CT does not show the real extent of the process. Nevertheless, given its availability, contrast-enhanced CT should be the primary imaging test, both to rule out other possibilities and to indicate other neuroimaging studies, in this case MRI and MR angiography. The results obtained when these two techniques are performed simultaneously, even without contrast administration, are sufficient for diagnosis and are comparable to those at conventional angiography, but without the risks entailed and without exposing the patient to ionizing radiation.

Lamotrigine-induced rash--worth a rechallenge

OBJECTIVES

The only serious adverse event associated with lamotrigine (LTG) treatment is a hypersensitivity reaction primarily presenting as a rash. Despite this concern, LTG is an antiepileptic drug (AED) with one of the most favorable efficacy/tolerability ratio compared with the new as well as the old AEDs. Thus, this study aimed to evaluate the results of rechallenge with LTG after the initial rash.

MATERIAL AND METHODS

A total of 688 patients (350 as monotherapy, and 338 as add-on therapy) with either idiopathic generalized epilepsy or focal epilepsy were treated with LTG. The patients with LTG-induced rash were rechallenged to LTG. The dosage schedule was: 5 mg every day or every second day for 14 days, increased by 5 mg every 14th day to 25 mg a day. After achieving the daily dosage of 25 mg/day, the up-titration was completed following the current guidelines.

RESULTS

A total of 52 patients developed a rash. The LTG-induced rash occurred in 6%, where 12 (1.8%) developed a rash shown to be coincidentally associated with the initiation of LTG therapy. In their cases LTG was continued with success without intermission. Nineteen (38%) of the initial cohort were rechallenged with LTG, with a success rate of 84%.

CONCLUSION

This study is the first one to provide a successful recipe verified in time for the rechallenge with LTG after the initial drug-induced rash. Importantly, the concurrent use of valproate (VPA) was not found in this study to represent an additional risk factor for the occurrence of the rash during rechallenge with LTG. Our results agree with previous findings that women are more likely to develop the rash (P < 0.009).