Transverse sinus thrombosis in newborns: Clinical and magnetic resonance imaging findings

Neonatal transverse sinus thrombosis (TST) is considered a rare and severe sequela of birth injury. Clinical descriptions of this entity are few since most published series are postmortem studies. The advent of magnetic resonance imaging (MRI) allows recognition of TST ante mortem. We describe 4 full‐term infants with distinct clinical and neuroradiological features indicative of TST, which we suggest may be relatively common, with a wide spectrum of severity, including favorable outcome.

The advent of magnetic resonance imaging (MRI) allows recognition of TST ante mortem. We describe 4 full-term infants with distinct clinical and neuroradiological features indicative of TST, which we suggest may be relatively common, with a wide spectrum of severity, including favorable outcome. Baram  We present a series of full-term infants with similar clinical, electrophysiological, and cerebrospinal fluid (CSF) characteristics, all of whom had transverse sinus thrombosis on MRI.
Infants were evaluated neurologically when seizures wc:re suspected or hyperirritability and an abnormal electroencephalogram (EEG) were noted. Magnetic resonance images were performed on a General Electric 1.5 Tesla Signa system (General Electric, Milwaukee, WI). Slice thickness was 5 mm with a 1-mm gap. Unless other parameters are indicated in the text, T1-weighted spin echo (SE) sequences consisted of' TR 600 ms and TE 20 ms, and T2-weighted SE sequences consisted of T R 2,500 rns and TE 160 rns. All images were obtained from 10 to 21 days after birth. EEGs were performed according to the recommendations of the American Electroencephalography Society for studies in infants [GI.

Results
The clinical characteristics of the 4 patients as well as the results of CSF analysis (in 3 cases) and the salienl: features of their EEGs are depicted in the Table. A sample history of the first evaluated infant follows.
Baby S was a term product of a pregnancy cornplicatied by maternal fever. The patient was rneconiurn stained at birth; Apgar scores were 4 and G at 1 and 5 minutes, respectively.
Irritability and jitteriness were noted in the nursery but the infant experienced no true seizures. An evaluation for sepsis revealed xanthochromic CSF. Neurological examination confirmed the irritability and, in conjunction with the CSF findings, prompted neuroradiological evaluation. A CT scan was normal; however, the torcula, distal straight sinus, and transverse sinus were considered thrombosed by MRI criteria. EEG showed a normal background activity with excessive central and right temporal spikes and sharp waves. The child's irritability resolved gradually over 2 to 3 weeks.
Neurological follow-up examination was normal.
Figures 1 and 2 demonstrate the appearance of dural sinuses involved in the thrombotic process. The dominant right transverse sinus appears hyperintense on T1-weighted images in all cases. Additionally, nonflowing blood is seen in the torcula in Figure 2, which also demonstrates extravasated blood in the posterior fossa, probably in the subdural space.

Discussion
In this report we describe a small group of newborns with TST and a benign outcome. This is at variance with most reported series of sinus thrombosis in infancy C1, 2, 51. Few clinical descriptions of the course of newborns with TST are available (73. Published clirnical reports usually describe a catastrophic, rapidly fatill brainstem compression by an associated infratentorial hematoma [ S } . A slower course, with a prodromal "normal" phase followed by signs of increased intracranial pressure, brainstem compression, and death has also been described 171. Recently 2). McArdle and associates 11 51 described the MRI appearance of 6 venography-proven cases of transverselsigmoid sinus thrombosis, and distinguished thrombus from the increased signal caused by turbulent slow flow by the difference in signal intensity from the first to the second echo. The change in signal intensity for thrombus was quantitatively less than that observed with slow flow. Bauer and colleagues [4] algo described the typical subacute hyperintense appearance of sinus thrombosis on both T1-and T2-weighted images. The MRI scans of our patients, obtained 10 to 21 days after birth, reveal the hyperintense signal of sinus thromboses, as demonstrated in both TIand T2-weighted images (see Figs 1 and 2). The associated subdural and subarachnoid hemorrhages are also seen (see Fig 2).