Pregnancy and Puerperium

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              Cerebral Venous Thrombosis Associated With
                       Pregnancy and Puerperium
                                                  Review of 67 Cases
                                   Carlos Cantu, MD; Fernando Barinagarrementeria, MD

            Background and Purpose: Cerebral venous thrombosis is characterized by its clinical pleomorphism and
          pathogenetic variability. We studied 67 patients with cerebral venous thrombosis associated with
          pregnancy and puerperium and compared them with 46 other cases unrelated to obstetric causes to
          disclose differences in their clinical presentation, neuroradiological findings, clinical course, and
            Methods: In this retrospective study, we analyzed the clinical, laboratory, and neuroimaging findings of
          113 patients collected consecutively at our institute. The diagnosis of cerebral venous thrombosis was
          confirmed by angiography, magnetic resonance imaging, or neuropathological study.
            Results: Patients with cerebral venous thrombosis associated with pregnancy and puerperium were
          younger (average age, 26 versus 36 years), and in most, the onset of symptoms was acute (82% versus 54%;
          P=.003). The evolution of symptoms reached a plateau within 10 days in 70% of patients with thrombosis
          from obstetric causes, compared with only 45% in those from other causes (P=.01). Anemia was more
          frequent in the obstetric group (64% versus 26%; P=.00001). There were no differences regarding
          neurological and neuroradiological findings. Although the initial severity of illness was similar in both
          groups, the final outcome was considered good in 80%, of patients with obstetric causes, compared with
          58% of patients with other causes (P=.01); mortality rates were 9% and 33%, respectively (P=.002).
            Conclusions: Cerebral venous thrombosis associated with pregnancy and puerperium has a more acute
          onset and a better prognosis than thrombosis due to other causes. These findings might be helpful in the
          diagnostic and therapeutic strategies for patients with cerebral venous thrombosis. (Stroke. 1993;24:
            KEY WoRDs * pregnancy * puerperium * thrombosis * women

In 1828, Abercrombiel published the first clinico-                     1. Angiographic evidence of CVT5,6: total or partial
       pathological description of a case of puerperal              lack of filling of at least one sinus on at least two
       cerebral venous thrombosis (CVT). Since then,                projections. When the lack of filling involved only the
the association of CVT with pregnancy and puerperium                anterior portion of the superior sagittal sinus or only
has been recognized, especially in developing coun-                 one lateral sinus, additional signs of CVT were re-
tries.2-4 Of 113 cases of aseptic CVT seen in the past 20           quired, such as evidence of delayed venous emptying or
years at the National Institute of Neurology and Neu-               development of collateral circulation.
rosurgery in Mexico City, 67 were diagnosed in the                     2. Evidence of CVT via neuropathological study:
puerperal period, 5 during pregnancy, and in 1 patient              presence of thrombosis of venous sinuses or cerebral
after abortion. The aim of this paper is to analyze these           veins, with or without associated venous infarction.
67 cases and compare them with the remaining 46 cases                  3. Magnetic resonance imaging (MRI) evidence of
of CVT, which were not related to obstetric causes, to              CVT7: absence of voiding on TI weighted images with
disclose some clinical, paraclinical, or prognostic fea-            isointensity or hypointensity on T2 weighted images
tures that may be distinctive for patients with CVT                 during the first few days and hyperintensity of the
                                                                    lumen of the sinus on T1 and T2 weighted images from
associated with pregnancy and puerperium.                           about 1 week to 1 month after thrombosis.
                 Subjects and Methods                                  Patients were excluded when (1) clinical or radiolog-
                                                                    ical records were incomplete, (2) radiological studies
   Patients with a diagnosis of aseptic CVT admitted to             were inconclusive, (3) there was cavernous sinus throm-
our hospital were included in this study when they                  bosis, or (4) CVT was associated with sepsis. Of 67
satisfied any of the following criteria:                            patients with CVT associated with pregnancy and pu-
                                                                    erperium (group 1), 50 were included on the basis of
                                                                    angiographic criteria, 10 by MRI criteria, and 7 by
  Received March 24, 1993; final revision received July 18, 1993;   neuropathological criteria. Of the 46 cases with CVT
accepted August 3, 1993.                                            unrelated to obstetric events (group 2), 26 were in-
  From the Stroke Clinic, National Institute of Neurology and
Neurosurgery, Mexico City.                                          cluded on the basis of angiographic criteria, 11 by
  Correspondence to Dr Carlos Cantu, Instituto Nacional de          neuropathological criteria, and 9 by MRI criteria.
Neurologia y Neurocirugia, Insurgentes Sur 3877, Tlalpan, Mexico       The following characteristics were compared between
14269 DF, Mexico.                                                   the two groups:
                                                  Canti and Barinagarrementeria Cerebral Venous Thrombosis           1881

        TABLE 1. Clinical Profile and Evolution of Cerebral Venous Thrombosis
                                                    Group 1 (n=67)             Group 2 (n=46)
                                                    n           %             n             %                P
         Acute                                      55         82.1           25           54.3            .003
         Insidious                                  12         17.9           21           45.7
         Progressive                                48         71.6           24           52.2            .03
         Nonprogressive                             19         28.4           22           47.8
         Time elapsed between onset and
         stabilization of symptoms
         <10 days                                   47         70.1           21           45.7            .01
         >10 days                                   20         29.9           25           54.3
         Time elapsed between onset and
         <1 week                                    38         56.7           10           21.7            .0002
         1-3 weeks                                  25         37.3           16           34.8
         >3 weeks                                    4          6.0           20           43.5

   1. Clinical: mode of onset, classified as "acute"            Treatment for both groups was mainly conservative.
(symptoms appeared suddenly or developed in less than         Only five patients with puerperal CVT received antico-
48 hours) or "insidious" (gradual development of symp-        agulation therapy, and their data were excluded from
toms over several days or weeks); presenting symptoms;        the final outcome evaluation tables because it is well
clinical course, classified as "progressive" (development     known that anticoagulation in the early stages of CVT
of additional symptoms and/or worsening of the pre-           modifies its natural history.8'9
senting symptoms) or "nonprogressive" (presenting               Differences between groups were tested for statistical
symptoms remained stable or tended to subside without         significance using multivariate analysis with 2x 2 contin-
development of additional symptoms); neurological             gency tables, x2 test, and Fisher's exact test.
signs and symptoms; time elapsed between the onset                                      Results
and stabilization of symptoms; and time elapsed be-
tween onset and diagnosis.                                       The mean age of group 1 patients was 26 years (range,
   2. Hematologic: anemia (hemoglobin <12 g%), leu-           16 to 44 years) and of group 2, 36 years (range, 15 to 77
kocytosis (white blood count >10 000/mm3), thrombo-           years). Thirteen male patients were included in group 2.
cytosis (platelet count >450 000/mm3), erythrocyte sed-          Regarding puerperal patients, 21 cases of CVT
imentation rate (ESR) (normal 0 to 20 mm/h), and              (34.4%) occurred during the first week after delivery (9
polycythemia (hematocrit >60%).                               within the first 48 hours) and 36 (59%) during weeks 2
   3. Cerebrospinal fluid (CSF) data: opening pressure        and 3 postpartum. Pregnant patients were affected in
(normal pressure <200 mm water), total protein (nor-          any trimester (1 in the first, 2 in the second, and 2 in the
mal value 15 to 45 mg/dL), and cell count (normal value       third trimester). In group 1, there were 43 multiparas
<5 cells/mm3).                                                (64.1%), 36 women (53.7%) from low or rural social
   4. Neuroimaging: evidence of CVT and associated            stratum, and 21 women (31.3%) whose delivery was
                                                              conducted at home by midwives and who did not have
parenchymal lesions detected by computerized tomogra-         proper prenatal care. Three patients had a history of
phy (CT) and MRI. Abnormalities considered as direct          venous thrombosis outside the central nervous system
signs of CVT on CT scan included the cord sign, the           during previous pregnancies (two instances of pelvic
dense triangle, and the empty delta sign. Hemorrhagic         venous thrombosis and 1 case of pulmonary embolism).
infarction was defined as patchy areas of high attenuation       Patients from group 2 had the following predisposing
with indistinct margins and a speckled or mottled appear-     factors for CVT: use of oral contraceptives (7 patients),
ance, whether separate or coalescent, within a venous         thrombocytosis in 4 patients, secondary polycythemia in
infarction. Intracerebral hemorrhage was defined as a         3 cases, circulating lupus anticoagulant in 2, and protein
homogeneous region of high attenuation.                       S deficiency in 2. In addition, an arteriovenous malfor-
   5. Sites of thrombosis within the cerebral venous          mation was present in 2 patients and metastatic carci-
system.                                                       noma in 1. In the remaining 25 cases, no predisposing
   6. Clinical evaluation at the time of discharge from       factors were found.
hospital: classified as "good outcome" when patients             Clinical, laboratory, and neuroradiological findings
recovered fully or had partial functional recovery with       are displayed in Tables 1 through 5. Results of the final
only mild sequelae and "poor outcome" when sequelae           clinical evaluation are shown in Table 6. Several differ-
were serious or the patient died.                             ences were relevant: (1) Patients of group 1 had an
1882       Stroke Vol 24, No 12 December 1993

TABLE 2. Presenting Symptoms in 113 Patients With                          TABLE 4. Hematologic and Cerebrospinal Fluid
Cerebral Venous Thrombosis                                                 Findings in Cerebral Venous Thrombosis
                             Group 1                       Group 2                                     Group 1             Group 2
                              (n=67)                        (n=46)                                      (n=67)              (n=46)
                         n          %                  n             %                                n          %        n          %
Headache                49         73.1               28            60.8   Hematologic
Seizures                                                                   Anemia*                    43        64.1     12       26.0
Generalized              1             1.4            5             10.8   Leukocytosis               24        35.8     20       43.4
Focal                    7             8.9            2              4.3   Increased erythrocyte
                                                                           sedimentation ratet      26/47       55.3    12/41     29.2
Focal signs
                                                                           Thrombocytosis              2         2.9      6       13.0
Motor                    1             1.5            5             10.9
Sensitive                6             9.0            4              8.7   Cerebrospinal fluid
                                                                           Normal                    13/46      28.2     6/27     22.2
Disorders of
consciousness            3             4.5             2             4.3   Increased opening
                                                                           pressure                  19/46      41.3    15/27     55.5
                                                                           Abnormal cytological
acute onset more often (P=.003); (2) although the                          exam                     29/46       43.4    11/27     20.7
course of illness was progressive in more patients of                      Hemorrhagic               11/46      23.9     9/27     33.3
group 1 (P=.03), symptoms tended to become stable or
began to subside in a shorter interval (P=.01); (3)                          *P=.00001, tP=.01.
diagnosis was established within a week of onset in a
higher proportion of patients of group 1 (P=.0002); (4)                    better outcome (P=.01) and a lower mortality rate
concomitant extraneurological thrombosis was more                          (P=.002).
frequent in group 1 (22.3% versus 6.5%; P=.01); (5)                           There were no differences between groups regarding
anemia was more often present in group 1 (P=.00001)                        sites of thrombosis within the cerebral venous system
and was usually related to an inadequate supply of iron                    (Table 7).
during pregnancy with or without blood loss during
delivery and puerperium (hypochromic, 26/43, 60.5%;                                                Discussion
normochromic, 17/43, 39.5%); (6) although the severity                        A wide variety of well-known conditions may cause or
of illness was similar in both groups, with comparable                     predispose to CVT, and their relative importance may
neurological and neuroradiological findings, CVT asso-                     vary in different areas of the world.9-14 In the present
ciated with pregnancy and puerperium had a much                            study. 60% of cases were associated with pregnancy and
                                                                           puerperium (ratio group 1/group 2, 1.5). This complica-
TABLE 3. Neurological Findings in CVT                                      tion is also common in India, with a prevalence of
                                                                           4.5/1000 obstetric admissions.2.15 In accordance with an
                                       Group 1              Group 2        obstetric CVT series,16 symptoms of CVT appeared in
                                           (n=67)               (n=46)     the first 3 weeks after delivery in the majority of cases
Findings                            n           %           n        %     and, as in the Indian series, women who had home
                                                                           deliveries and poor prenatal care were more often
Headache                           59          88.0        32       69.5   affected. CVT should be suspected in any woman who
Focal signs                        53          79.1        35       76.0   develops neurological symptoms in the immediate post-
Motor                              52          77.6        33       71.7   partum period, since nearly 15% of our cases occurred
                                                                           in the first 2 days after a normal childbirth. CVT
Sensitive                          25          37.3        13       28.2   occurred 13 times more often during puerperium than
Aphasia                            17          25.3        10       21.7   during pregnancy. Although in the Indian population,
Disorders of consciousness         42          62.6        27       58.6   multiparas are more often affected than primiparas, in a
Somnolence                         24          35.8         9       19.5
                                                                           proportion of 4: 1,17 in our population this difference
                                                                           was not so striking (1.8:1).
Stupor/coma                        16          23.9        15       32.6      In this study, we found a high frequency (70%) of
Confusion                           2           2.9         3        6.5   parenchymal lesions (venous infarcts and intracerebral
Seizures                           40          59.7        29       63.0   hemorrhages) that manifested as focal neurological signs,
                                                                           epileptic seizures, disorders of consciousness, intracranial
Generalized                        18          26.9        16       34.8   hypertension, nuchal rigidity, and hemorrhagic CSF.
Focal                              22          32.8        13       28.2   These findings also explain the high mortality rate in our
Bilateral pyramidal signs          28          41.7        18       39.1
                                                                           whole series (18.5%). This is in contrast with reports from
                                                                           other countries18-20 and illustrates the great clinical and
Papilledema                        27          40.2        24       52.1   neuroradiological pleomorphism of this condition world-
Nuchal rigidity                    22          32.8        12       26.0   wide. Our series is characterized by a low frequency of
Isolated intracranial                                                      isolated intracranial hypertension and absence of Behcet's
hypertension                           5        7.4         8       17.3   disease as a cause of CVT. Even when we consider these
                                                                           variations, there seem to be important differences be-
                                                             Cantu and Barinagarrementeria Cerebral Venous Thrombosis                1883

TABLE 5. Neuroradiological Findings
                                                           Computed Tomographic Scan                    Magnetic Resonance Imaging
                                                         Group 1                Group 2                 Group 1                 Group 2
                                                           (n=59)                (n=36)                  (n=19)                  (n=20)
Findings                                          n               %        n            %          n             %         n              %
Normal                                             5             8.4        4         11.1          0            0          0              0
Signs of cerebral venous thrombosis               19            32.2*      13        36.1*         17           89.4       19             95
Parenchymal lesions
Nonhemorrhagic venous infarct                     16            27.1        7        19.4           3           15.7        2             10
Hemorrhagic venous infarct                        21            35.5       12        33.3          10           52.6       11             55
Intracerebral hemorrhage                           6            10.1        5        13.8           2           10.5        4             20
Unilateral lesion                                 25            42.3       15        41.6           8           42.1       12             60
Bilateral lesions                                 18            30.5        9        25             7           36.8        5             25
  *Delta sign, dense triangle, or empty delta sign.

tween CVT associated with pregnancy and puerperium                       role, such as protein S deficiency, which is common
and that with nonobstetric causes. The clinical picture of               during pregnancy and puerperium.23 25 Deficiency of
the former featured a disease with sudden or acute onset,                protein S has been reported in previous cases of CVT in
with a progressive course that tends to become stable or                 obstetric patients.11,26.27 The higher prevalence of extra-
begin to subside in a short time (5 to 10 days). In                      neural thrombosis in CVT associated with pregnancy
nonobstetric cases, the onset was insidious in about half                and puerperium may represent the systemic repercus-
the patients; the course could be progressive or not and                 sion of a hypercoagulable state.
tended to be stable after 10 days in >50% of patients.                      Although the disease was of similar severity in both
These findings suggest that, in obstetric cases, the patho-              groups, the outcome was more favorable in obstetric
physiological process leading to venous occlusion develops               patients. Possibly, CVT in obstetric subjects is a more
faster but is usually self-limited and resolves itself in a              benign entity than the one affecting other types of
shorter time. Further evidence for this is the shorter                   patients because of a more limited and transient occlu-
period between onset of symptoms and diagnosis in ob-                    sion, with rapid sinovenous recanalization by spontane-
stetric patients; however, it should be born in mind that                ous thrombolysis or development of collaterals.
puerperium represents an important clue for suspecting
CVT.                                                                     TABLE 7. Site of Venous Occlusion in 113 Patients With
   Another important difference was the high frequency                   Cerebral Venous Thrombosis
of anemia in obstetric patients, probably reflecting a
poor diet during pregnancy and/or blood loss during                                                        Group 1              Group 2
delivery. The high prevalence of anemia has been                                                           (n=67)               (n=46)
recognized in most obstetric series of CVT23 and de-                                                  n           %        n          %
serves further study to clarify its role in the pathogen-
esis of this entity.                                                     SSS                         60         89.5      45        97.8
   Traditionally, the most frequently postulated mecha-                                              22         32.8*     11        23.9*
nism involved in CVT in obstetric patients is a hyper-                   LS                          23         34.3      20        43.4
coagulable state2122 associated with dehydration and
anemia. However, other factors may play an important                                                   1         1.4*       1         2.1*
                                                                         DVS                         17         25.3      10         21.7
TABLE 6. Final Outcome in 108 Cases of Cerebral                                                        4         7.4*       0         ...
Venous Thrombosis
                                                                         CCV                         13         19.4      14         30.4
                           Group 1            Group 2                    SSS+LS                      16         23.8      15         32.6
                           (n=62)*             (n =46)
                                                                         SSS+CCV                       9        13.4        8        17.3
                       n         %        n            %            P
                                                                         SSS+DVS                       6         8.9        5        10.8
Good outcome                                                    .01
                                                                         SSS+LS+DVS                    4         5.9        2         4.3
Total recovery        31        50.0     24        52.1
                                                                         SSS+CCV+DVS                   2         2.9        2         4.3
Mild sequelae         19        30.6      3            6.5                                                       1.4        1         2.1
                                                                         SSS+CCV+LS                    1
Poor outcome                                                             SSS+CCV+LS+DVS                0         ...       1          2.1
Severe sequelae         6        9.7      4            8.7
                                                                                                                  1.4      0
                                                                         CCV+LS                        1                             ...
Death                   6        9.7     15        32.6         .002
                                                                           SSS indicates superior sagittal sinus; LS, lateral sinus; DVS,
   *Five patients who had good outcome received anticoagula-             deep venous system; and CCV, cortical cerebral veins.
tion and were excluded from statistical analysis.                          *Isolated venous occlusion involvement.
1884         Stroke Vol 24, No 12 December 1993

   Prognosis and treatment are the most controversial                        13. Averback P. Primary cerebral venous thrombosis in young adults:
issues of cerebral venous thrombosis. Prognosis is quite                         the diverse manifestations of an underrecognized disease. Ann
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