Pulse-synchronous tinnitus can be an important indicator of chronic IH. It is described as a whooshing, whistling, humming or marching noise heard in one or both ears that is in sync with the pulse. It is also a subjective noise; it can only be heard by the person who experiences it.
This form of tinnitus is caused by high intracranial pressure compressing blood vessels. It often accompanies severe headache and the other symptoms of chronic IH. But it can also happen by itself. In fact, pulse-synchronous tinnitus can be the presenting symptom of the disorder and is recognized as part of the diagnostic criteria for chronic IH.
While pulse-synchronous tinnitus that occurs with chronic IH is not associated with hearing loss, it can be deeply disruptive to daily life and especially, sleep, which in turn can impact the severity of other symptoms.
Lowering intracranial pressure helps to alleviate pulse-synchronous tinnitus. Some have found temporary relief from pulse-synchronous tinnitus by sleeping with their head elevated at a 45-degree angle. Many times, the noise completely and dramatically disappears when intracranial pressure is lowered during a lumbar puncture. But unfortunately, pulse-synchronous tinnitus can return when intracranial pressure becomes elevated again. It also may occur during physical activity or movement that increases the heart rate or increases blood flow.