Washington DC Metro Medical Malpractice Lawyer Blog

While most Arnold Chiari Type I malformations do not result in any symptomatology and are never detected, some individuals develop headaches in conjunction with this congenital malformation. These headaches are typically occipital in nature and may be associated with nausea and vomiting. In some instances, age (in the range of 24-40 years) combined with triggering events such as trauma or pregnancy, will cause a Chiari Type I malformation to decompensate. Decompensation of a Chiari Type I malformation produces significant cerebrospinal fluid ("CSF") problems below the cerebellum in the posterior cranial fossa and the spinal cord. Decompensation of a Chiari Type I malformation with an associated syrinx leads to the progressive development of neurological symptomatology related to the anatomical functions of posterior fossa brain structures, manifesting as vertigo, ataxia, focal neurological findings (e.g., foot drop), and severe headaches. Symptoms of a decompensated Chiari Type I malformation with syrinx are similar and overlapping with symptoms of other intracranial processes such as brain cancer or benign intracranial tumors. The Gold Standard for diagnosis of this condition is an MRI of the skull and brain.

The natural history of decompensated Chiari Type I malformation with syrinx formation causes severe morbidity and even mortality if not treated in a timely manner. The treatment for decompensated Chiari Type I malformation with syrinx is neurosurgical and involves decompression of the arrested CSF flow by performance of a craniectomy at the level of the foramen magnum, producing space to allow normal CSF flow and reabsorption of syrinx and hydromyelia fluids. A duraplasty is performed to create space around the brain tissues, thereby allowing for long-term decompression and promoting CSF flow. Neurosurgical decompression of a decompensated Chiari Type I malformation is a life-saving procedure and has to be performed on the basis of clinical neurological findings.

In progressive neurological disease, immediate surgical decompression is required, and in such patients the earlier the decompression is performed the more successful the long-term results will be. Typically, neurosurgical decompression reverses all symptomatology and provides for an outstanding long-term prognosis without permanent neurological sequelae and without the need for further medical intervention over the remainder of the patient's life.

RL would likely have recovered without residual neurological symptomatology if she had been diagnosed and treated in a timely manner. The record documents that within 10 days of diagnosis RL was treated neurosurgically and that the treatment was successful. RL's congenital malformation would not have led to the development of permanent neurological sequelae if she had been referred for neurological and neurosurgial evaluation in a timely manner.

In the case of RL, her prenatal care failed to meet the standard of care for medical management of a pregnant patient. At no time during her entire pregnancy, did any of her healthcare providers entertain a differential diagnosis to explain her persistent neurological symptoms. A differential diagnosis is a method used by physicians to rank order in terms of seriousness and frequency the potential diagnostic possibilities most consistent with the patient's complaints. For RL the standard of care for management of her pregnancy required the entry in the record of a differential diagnosis that included a central nervous system illness. Moreover, the standard of care required that RL undergo an MRI of the head, brain, cervical spine, thoracic spine, and lumbosacral spine to exclude intracranial or intrathecal pathology to evaluate the cause of her severe occipital headaches, persistent supine vertigo, left leg weakness and unremitting severe back pain. When sufficient maternal indications existed, the performance of MRIs during pregnancy is both appropriate and safe.

Normal labor and delivery, especially maternal voluntary expulsive efforts, are associated with Valsalva-like pressures that can contribute to herniation of already crowded brain structures through the foramen magnum, the opening at the base of the skull. The Valsalva maneuver, which involves forced expiratory effort with closed nose and mouth to inflate the eustachian tubes and middle ears, should be avoided in patients with Chiari Type I malformation because of the risk of increasing intracranial pressure. Maternal pushing, associated with labor, is essentially a prolonged and forced series of Valsalva maneuvers. Normal labor and delivery, especially during the second stage of labor, created a significant risk of brain stem and spinal cord crowding and compression injury to RL, and should have been avoided.

An MRI of the skull and head should have been performed duirng her pregnancy and would have timely diagnosed RL's condition, required that she be managed as a high risk pregnant patient, and required the performance of an early cesarean section delivery with the avoidance of labor and increased intracranial pressure.

When RL first sought legal consultation with Stein, Mitchell & Mezines in June 2001, she presented with a constellation of neurological symptoms - primarily loss of equilibrium, ocular nystagmus, and confusion which did not carry a clear diagnosis. RL knew one thing - that she was not treated in a timely fashion by her health care providers at Malcolm Grow Medical Center at Andrews Air Force Base. It all happened during her second pregnancy in 2000 during which she suffered severe headaches and bouts of dizziness. Five months after she delivered her baby, her treating physicians performed an MRI of her skull and found that she had severe cerebellum and brainstem compression. She acquired this syndrome due to a failure to timely detect and treat a decompensated Arnold Chiari Malformation ("ACM"). This is a congenital condition which allows the cerebellum and brain stem to slide through the foramen magnum at the base of the skull causing direct compression injury to the posterior fossa brain structures and cervical spine.

This condition should have been diagnosed during her second pregnancy, when her symptoms were wrongfully ascribed to her pregnancy, leading to confusion and a misdiagnosis which resulted in repetitive assurances to RL and her husband that she was doing fine. The failure to perform a neurological evaluation and MRI of her skull and vertebral column during her pregnancy resulted in a late diagnosis of her decompensated ACM condition. Regretfully, the diagnosis was arrived at belatedly, only after RL was allowed to undergo a vaginal delivery of her baby (which is known to produce further compression injuries secondary to valsalva maneuvers which occur during labor and delivery and which are known to increase intracranial pressure). The Chairman of the Department of Neurosurgery at Walter Reed Medical Center made the correct diagnosis in March 2001 and performed life-saving neurosurgical decompression of RL's posterior fossa.

After a two-week trial in federal court in Greenbelt, Maryland, U.S. District Judge Roger W. Titus found for Mrs. Lawson on all issues and awarded her $5.26 million. The total verdict included future care costs of $3.7 million, lost net income of $938,982, past medical expenses of $11,252, and pain and suffering in the amount of $590,000 (the statutory limit under Maryland law).

In Lawson v. US., 454 F.Supp. 2d 373 (D. Md. 2006), Judge Roger W. Titus awarded my client $5.26 million for severe neurological injuries suffered as a result of a negligent failure to timely diagnose and treat her decompensated Arnold Chiari Malformation which became symptomatic during her second pregnancy.

Arnold Chiari Type I malformation is a condition in which the cerebellar tonsils protrude through the foramen magnum (the large hole at the base of the skull) and into the spinal canal. In its pure form, a Chiari Type I malformation shows cerebellar tonsils down to the C1-C2 region but with normal brain stem location. The condition arises in approximately 1% of the population, and most cases are incidentally diagnosed by MRI. With a Chiari Type I malformation, the posterior fossa of the skull is pathologically small and lies in the subocciput between the foramen magnum and the tentorium, a strong fold of dura mater which serves as a membranous cover or horizontal partition below the basal surface of the occipital and temporal lobes of the cerebral hemisphere. The boundaries of the posterior fossa are marked by boney ridges. The brain structures within the posterior fossa (i.e., the cerebellum, hindbrain, pons, vermis, and cerebellar tonsils) cannot be fully contained in the congenitally malformed fossa and emerge below the foramen magnum. In addition, the cerebellum and hindbrain are slightly elongated and are compressed in the direction of the spinal cord. Cerebellar tonsils less than 5 mm below the foramen magnum are common, but that is the current lower limit of normal usually cited in the medical literature.

While most Chiari Type I malformations do not cause any symptoms and are never detected, some people develop headaches due to this congenital proboem. The headaches are typically occipital and may be associated with nausea and vomiting. In some instances, a patient's age (usually 24-40 years), combined with triggering events such as trauma or pregnancy, will cause a Chiari Type I malformation to decompensate, producing significant cerebrospinal fluid ("CSF") collections below the cerebellum in the posterior cranial fossa and the spinal cord. Decompensation of a Chiari Type I malformation with an associated syrinx (fluid along the spinal cord and adjacent to central canal) leads to the progressive development of symptoms relating to the anatomical functions of posterior fossa brain structures and manifesting as vertigo, ataxia, focal neurological findings (e.g., foot drop), and severe headaches. Symptoms of a decompensated Chiari Type I malformation with syrinx are similar to symptoms of other intracranial processes such as brain cancer or benign intracranial tumors.

The gold standard for diagnosing this condition is an MRI of the skull and brain, which can be safely performed during pregnancy. With progressive neurological disease, immediate surgical decompression is required, and in such patients the earlier the decompression is performed the more successful the long-term results will be. Timely neurosurgical decompression usually reverses all symptomatology and provides for an outstanding long-term prognosis with no permanent neurological sequelae or need for further medical intervention during the rest of the patient's life.

Helpful Links:

NINDS Chiari Malformation Information Page

World Arnold Chiari Malformation Association