The leading cause of death still remains lead poisoning however. M. H. Stevens and his team have concluded that high levels of lead deep in the bone sampled from Beethoven's skull suggest repeated exposure over a long period of time rather than limited exposure prior to the time of death. Among other evidence, the finding of shrunken cochlear nerves at his autopsy is consistent with axonal degeneration due to heavy metals such as lead. Chronic low-level lead exposure causes a slowly progressive hearing loss with sensory and autonomic findings, rather than the classic wrist drop due to motor neuropathy from sub-acute poisoning. Beethoven's physicians thought that he had alcohol dependence. He particularly liked wine that happened to be tainted with lead, therefore Beethoven's chronic consumption of wine tainted with lead is a better explanation of his hearing loss than other causes.